REVIEW | doi:10.20944/preprints201908.0258.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: circRNAs; gastric cancer; EMT
Online: 25 August 2019 (17:01:23 CEST)
With the continuous progress in modern medicine, the early detection rate of gastric cancer has increased, and the mortality rate has decreased. However, gastric cancer remains the third leading cause of cancer-related death worldwide, with a high recurrence rate. Metastasis is the leading cause of death and recurrence of gastric cancer, which greatly hinders treatment success. Cancer development is a complex process involving multiple sequential steps. In the metastatic cascade, local invasion may be considered an initial, crucial step in the development of a malignant tumor, which leads to distant metastasis. Epithelial-mesenchymal transformation (EMT) is one of the most important developmental processes that occur during tumor invasion. EMT confers certain basic abilities to cancer cells, such as migration, invasion and anti-apoptotic ability, thus initiating and increasing metastasis. However, little is known about the molecular mechanisms that promote EMT and gastric cancer cell metastasis. A number of recent studies have found that circular RNAs（circRNAs）are associated with gastric cancer EMT, regulating the EMT process and promoting the occurrence and development of tumors. Because of their unique continuous circular structure, circRNAs have relatively high stability in plasma and cells, making them more suitable as diagnostic biomarkers in malignant tumors. Therefore, understanding the mechanism of circRNAs in EMT in gastric cancer is an important research direction to actively prevent tumor metastasis and improve the therapeutic effect on advanced malignant tumors.
ARTICLE | doi:10.20944/preprints202202.0066.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: serum leptin; proximal gastric cancer
Online: 4 February 2022 (07:31:59 CET)
Background: The aim of the present study was to determine the correlation between obesity, serum levels of leptin and proximal gastric cancer. Methods: Sixty-four gastric cancer patients operated on with curative intent were included in the study. We determined the correlation between the preoperative serum levels of leptin and the tumor`s location. Results: Serum leptin levels were correlated significantly with the proximal third location (p = 0.04), gastric outlet obstructing tumors (p < 0.0001), CRP levels (p = 0.03) and BMI (p < 0.0001). Patients with high serum levels of leptin had significantly more intestinal types of gastric cancer (p = 0.033) and better differentiation compared to patients with low serum leptin levels (p = 0.009). The linear regression model determined the proximal tumor location (beta: 0.467; p = 0.045), BMI (beta: 0.657; p = 0.001), high preoperative serum albumin (beta: 0.563; p = 0.016) and the presence of pyloric stenosis (beta: 0.525; p = 0.006) as related significantly to serum leptin levels. The Cox proportional hazard model identified age (HR: 0.003; 95%CI: 0-0.794; p = 0.041), preoperative serum levels of leptin (HR: 0.125; 95%CI: 0.018-0.887; p = 0.037) and the number of extracted LNs (HR: 0.001; 95%CI: 0-0.677; p = 0.038) as independent prognostic factors. Conclusions: Serum levels of leptin were significantly elevated in patients with proximal gastric cancer, suggesting that the leptin`s effect might be due to its systemic secretion. This might explain the higher incidence of proximal gastric cancer in obese patients. Elevated serum leptin levels were an independent prognostic factor.
ARTICLE | doi:10.20944/preprints202012.0682.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: interleukin-33; gastric epithelium; proliferation; apoptosis; cell cycle; gastric cancer
Online: 9 March 2021 (13:12:02 CET)
Background: Interleukin (IL)-33 is a member of interleukin (IL)-1 family of cytokines which has been linked to the development of inflammatory conditions and cancer in the gastrointestinal tract. This study is designed to investigate whether IL-33 has direct effect on human gastric epithelial cells (GES-1) and on human gastric adenocarcinoma cell line (AGS) and gastric carcinoma cell line (NCI-N87), assessing its role in regulation of cell proliferation and cell cycle, apoptosis and necrosis. Cell cycle regulation was also determined in ex vivo gastric cancer samples obtained during endoscopy and surgical procedures. Methods: cell lines and tissue samples underwent stimulation with rhIL-33. Proliferation was assessed by XTT and CFSE assay, we also evaluated apoptosis by Caspase 3/8 Activity assay and Annexin V assays. Cell cycle were analyzed by means of Propidium Iodine assay and gene expression regulation was assessed by RT-PCR Profiling. Results: we found that IL-33 has an antiproliferative and proapoptotic effect on cancer cell line, while it can stimulate proliferation and reduce apoptosis in normal epithelial cell line. These effects are also confirmed by the analysis of cell cycle gene expression which showed a reduced expression of proproliferative genes in cancer cells, in particular genes involved in G0/G1 and G2/M checkpoint. These results are confirmed by the gene expression analysis on surgical and bioptic specimens. Conclusions: the aforementioned results indicate that IL-33 may be involved in cell proliferation in an environment- and cell type-dependent fashion.
REVIEW | doi:10.20944/preprints201707.0035.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: TGF-β; gastric cancer; microenvironment
Online: 14 July 2017 (11:59:25 CEST)
Gastric cancer is an intractable disease with a high incidence of peritoneal dissemination and obstructive symptoms (e.g. ileus, jaundice, and hydronephrosis) arising from accompanying marked fibrosis. Microenvironmental interactions between cancer cells and stromal cells are the suggested cause of the disease. Transforming growth factor (TGF-β) is an intriguing cytokine exhibiting dual roles in malignant disease, acting as an important mediator of cancer invasion, metastasis, and angiogenesis as well as exhibiting antitumor functions. Moreover, the TGF-β pathway contributes to the generation of a favorable microenvironment for tumor growth and metastasis throughout the steps of carcinogenesis. Among these effects, TGF-β induces the epithelial-to-mesenchymal transition with prometastatic functions, contributes to the conversion of stromal cells to carcinoma-associated fibroblasts, and suppresses the function of immune cells, which compromises the antitumor immune response, leading to cancer progression and stromal fibrosis. In this review, we address the role of the essential TGF-β signaling pathway in the regulation of the activities of components of the tumor microenvironment of gastric cancer and how this contributes to tumor progression and stromal fibrosis. We then explore the potential to optimize therapy that inhibits TGF-β signaling in the preclinical and clinical settings of gastric cancer.
ARTICLE | doi:10.20944/preprints202210.0305.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: gastric cancer; DNA methylation; TFF1; TFF2
Online: 20 October 2022 (11:07:15 CEST)
Gastric cancer (GC) is one of the most common malignancies around the world, and the incidence of GC is increasing in the past decades. In addition to genetic modifications, epigenetic alterations catalyzed by DNA methyltransferases (DNMTs) are a well-characterized epigenetic hallmark in gastric cancer. Nowadays, DNA methylation landscape is essential for maintaining the silence of tumor suppressor genes (TSGs). As an important group of peptide, TFF family has been confirmed to function as a TSG in various kinds of cancers. However, whether TFFs could be modified by DNA methylation in gastric cancer remains unknown. In this study, we initially screened out two expression profiles about GC from Gene Expression Omnibus (GEO) database. The higher expressions of TFF1 and TFF2 were observed in GC tumor tissues than normal tissues. Additionally, we illustrated that the expressions of TFF1/TFF2 were associated to the overall survival (OS) and tumor free survival (TFS) of GC patients via through the Kaplan-Meier analysis. Subsequently, the integrative analysis was performed to estimate the DNA methylation level of each site in TFF1/TFF2 CpG islands. Importantly, our findings indicated that hyper-methylation of cg01886855 and cg26403416 were separately responsible for the downregulation of TFF1 and TFF2 in GC samples. Besides, utilizing the gain of function assay, we demonstrated that TFF1/TFF2 could suppress the proliferation of GC cells. Based on these results, We identified that TFF1 and TFF2 acted as the putative tumor suppressors in gastric cancer, which suggested that TFFs could be two candidate biomarkers for predicting tumor recurrence in gastric cancer patients. Furthermore, these findings highlight a potential therapeutic approach in targeting the TFFs for the treatment of gastric cancer.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: MicroRNAs (miRNAs); gastric cancer; angiogenesis; VEGF; ramucirumab; biomarkers
Online: 31 December 2020 (07:20:49 CET)
Gastric Cancer (GC) is the fifth most frequently diagnosed malignant tumor and the third cause of cancer mortality worldwide. For advanced GC, a large number of novel drugs and combinations have been tested, but results are still disappointing and the disease incurable in the majority of cases. In this regard, it is critical to investigate the molecular mechanisms underlying GC development. Angiogenesis is one of the hallmarks of cancer with a fundamental role in GC growth and progression and ramucirumab, a monoclonal antibody binding to vascular endothelial growth factor-2 (VEGFR-2) is approved in the treatment of advanced and pretreated GC. However, no predictive biomarkers for ramucirumab have been identified so far. MicroRNAs (miRNAs) are a class of evolutionally conserved single-stranded noncoding RNAs playing an important role, via post-transcriptional regulation, in essentially all biologic processes such as cell proliferation, differentiation, apoptosis, survival, invasion, and migration. Notably, in our review, we focused on miRNAs involved in angiogenic pathways in GC. Moreover, we evaluated the possible prognostic and predictive role of angiogenesis-related miRNAs as novel biomarkers of GC.
BRIEF REPORT | doi:10.20944/preprints202308.2029.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Helicobacter pylori; ureC; phylogenetic tree; gastric cancer
Online: 30 August 2023 (07:16:25 CEST)
Helicobacter pylori (H. pylori) is known to play a significant role in the development of peptic ulcer diseases and gastric cancer. Previous studies have reported the existence of polymorphism in the ureC gene of H. pylori. However, the relationship between genetic sequence variations in ureC and the pathogenesis of peptic ulcer diseases remains unclear. We aimed to investigate the associations between ureC sequence variations and the development of gastric ulcer and gastric cancer. PCR amplification and DNA sequencing to analyze ureC sequences, and conducted phylogenetic analysis using MEGA X software. Samples from Taiwanese patients with gastric ulcer and gastric cancer were included in this study. PCR was used to amplify the ureC gene from these samples, followed by DNA sequencing. The obtained sequences were then subjected to phylogenetic analysis using MEGA X software. In addition, ureC sequences from different geographical regions, including China and other countries, were included in the analysis for comparison. Analysis of the ureC se-quences from Taiwanese samples revealed that 6 out of 7 gastric ulcer samples clustered together in one group, while the sequences from 7 out of 8 gastric cancer samples were distributed across other groups. Phylogenetic analysis incorporating ureC sequences from different geographical regions showed that Taiwanese ureC sequences could be divided into two distinct groups, although the bootstrap values supporting this separation were low. Notably, the ureC sequences from China formed a distinct group with a high bootstrap value, separate from sequences from all other countries. There are two genotypes of ureC sequences present in Taiwanese samples, with one genotype showing a closer association with gastric cancer. Additionally, the ureC sequences from China appear to be unique and separate from those obtained from other countries, indicating the presence of genetic diversity in ureC sequences among H. pylori strains from different regions, potentially contributing to differences in disease outcomes. Further research is needed to elucidate the specific mechanisms by which ureC sequence variations may influence the pathogenesis of peptic ulcer diseases and gastric cancer.
REVIEW | doi:10.20944/preprints202210.0154.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Epstein–Barr virus; gastric cancer; immune microenvironment
Online: 11 October 2022 (10:43:36 CEST)
We have previously discussed the pathological characteristics, clinical characteristics, detection methods, pathogenesis, and treatment of Epstein–Barr virus (EBV)-positive gastric cancer, but we have not discussed the unique immune microenvironment in EBV-positive gastric cancer. Here, we reviewed studies on the immune microenvironment in EBV-positive gastric cancer and found that CD8+ T lymphocytes and a small number of CD204+ macrophages infiltrate the immune microenvironment in EBV-positive gastric cancer. Moreover, immune checkpoints, such as IDO1 and PD-L1, are expressed at high levels in EBV-positive gastric cancer. Lastly, we also analyzed the mechanisms underlying the formation of the immune microenvironment in EBV-positive gastric cancer. Our findings and conclusions have significance in clinical guidance and provide research direction for basic experiments.
REVIEW | doi:10.20944/preprints202308.0190.v2
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Savolitinib; MET-TKI; NSCLC; gastric cancer; renal cell carcinoma; pancreatic cancer
Online: 7 August 2023 (10:03:49 CEST)
Savolitinib is a highly selective small molecule inhibitor of the mesenchymal epithelial transition factor (MET) tyrosine kinase, primarily developed for the treatment of non-small cell lung cancer (NSCLC) with MET mutations. It is also being investigated as a treatment for breast, head and neck, colorectal, gastric, pancreatic, and other gastrointestinal cancers. In both preclinical and clinical studies, it has demonstrated efficacy in lung, kidney, and stomach cancers. Savolitinib is an oral anti-cancer medication taken as a 600 mg dose once daily. It can be used as a monotherapy in patients with non-small cell lung cancer with MET mutations, and in combination with epidermal growth factor receptor (EGFR) inhibitors for patients who have developed resistance to them. Furthermore, savolitinib has shown positive results in gastric cancer treatment, particularly in combination with docetaxel. As a result, this review aims to validate its efficacy in NSCLC and suggests its potential application in other gastrointestinal cancers, such as pancreatic cancer, based on related research in gastric and renal cancer.
ARTICLE | doi:10.20944/preprints202309.0975.v1
Online: 14 September 2023 (11:46:27 CEST)
Abstract: (1) Background: Surgery is the best curative option for Gastric Cancer (GC). However, morbimortality associated with surgery still a significant problem. Thus, it is essential to determine the preoperative surgical risk, to optimize outcomes in higher risk patients. (2) Methods: Patients who underwent curative gastrectomy between January 2010 and December 2013 were included, obtaining a sample of 131 patients, and the acuity of the scales understudy was evaluated. The predictive power of the scales was evaluated through calibration and discrimination. (3) Results and Conclusions: Regarding mortality, the scales demonstrated good calibration, with POSSUM and P-POSSUM obtaining the best O:E ratio. The scales presented good discrimination, with POSSUM showing the best result. Considering morbidity, the scales showed good calibration and discrimination. POSSUM and P-POSSUM seem to have potential in predicting morbidity and mortality when applied to the studied population, but there is a need for further studies in this area.
ARTICLE | doi:10.20944/preprints202004.0264.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: RBFOX3; HTERT; gastric cancer; promoter-binding protein; cancer biomarker
Online: 16 April 2020 (08:17:44 CEST)
Tumor invasion, metastasis, and recrudesce remain a considerable challenge in the treatment of gastric cancer (GC). Herein, we first identified that RBFOX3 (RNA binding protein fox-1 homolog 3) was significantly up-regulated in GC tissues and negatively linked to the survival rate of GC patients. RBFOX3 promoted cell division and cell cycle progression in vitro as well as in vivo. Furthermore, RBFOX3 increased cell invasion and migration ability. Interestingly, both the suppression of GC cell multiplication and invasion moderated by the silencing of RBFOX3 was rescued by HTERT up-regulation. Additionally, RBFOX3 augmented the resistance of GC cells to 5-fluorouracil (5-Fu) by repressing RBFOX3. Mechanistically, exogenous up-regulation of RBFOX3 triggered promoter activity and HTERT expression thereby enhancing the division and development of GC cells. Importantly, our findings revealed that RBFOX3 interacted with AP-2β to modulate the HTERT expression as demonstrated by co-immunoprecipitation analysis. In conclusion, our study indicates that high expression of RBFOX3 promotes GC progression and development but predicts worse prognosis by stimulating HTERT signaling. Moreover, the results suggest that the RBFOX3/AP-2β/HTERT pathway is a novel target for the development of therapeutic agents for the prevention and treatment of GC reappearance and metastasis.
ARTICLE | doi:10.20944/preprints202308.0543.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Gastric cancer; Blood-based miRNAs; Differentially expressed genes; Biomarkers; Bioinformatics
Online: 8 August 2023 (10:14:59 CEST)
In order to provide a new direction for the diagnosis and treatment of gastric cancer, the differentially expressed blood-based miRNAs in gastric carcinoma were obtained and analyzed from the datasets GSE113486, GSE112264 and GSE113740 by the SangerBox, the miRNA - target genes prediction, GO and KEGG functional enrichment analyses with DAVID 6.8, and the STRING database with Cytoscape, respectively. The correlation between the key miRNAs expression and the prognosis and diagnostic value of gastric cancer patients were detected by survival prognosis and ROC curve. QRT-PCR was used to detect the possible key miRNAs expression in human blood species. The dataset GSE108307 which shows the miRNAs affected by H. pylori infection was analyzed by GEO2R. The expression level of CagA and the clinically used gastric cancer markers were detected in human blood species for contrast. Five key blood-based miRNAs were determined, including hsa-miR-124-3p, hsa-miR-125a-3p, hsa-miR-29b-3p, hsa-miR-4276, and hsa-miR-575.The detection in human blood species as well as the cross analysis with H. pylori infection and clinically used markers expression suggested the importance and efficacy of the specific miRNAs in the early diagnosis and monitoring of gastric carcinoma. The study identified potential novel blood miRNA biomarkers of gastric cancer by bioinformatics and human blood species detection, which may give a new possibility of the important biomarkers for the diagnosis and prognosis of gastric cancer.
ARTICLE | doi:10.20944/preprints202310.1328.v1
Subject: Medicine And Pharmacology, Complementary And Alternative Medicine Keywords: gastric cancer prevention; nutraceuticals; phytochemicals; helicobacter pylori; aristolochia olivieri; apoptosis
Online: 20 October 2023 (09:25:15 CEST)
Abstract Background: Gastric cancer, particularly adenocarcinoma, is a significant global health concern. Environmental risk factors, such as Helicobacter pylori infection and diet, play a role in its development. Purpose: This study aimed to characterize the chemical composition and evaluate the in vitro antibacterial and antitumor activities of AOME. Additionally, morphological changes in gastric cancer cell lines were analyzed. Study design: AOME was analyzed using HPLC-MS/MS and its antibacterial activity against H. pylori was assessed using the broth microdilution method. MIC and MBC values were determined, and positive and negative controls were included in the evaluation. Methods: Anticancer effects were assessed through in vitro experiments using AGS, KATO-III, and SNU-1 cancer cell lines. The morphological changes were examined through SEM and TEM analyses. Results: AOME contained several compounds, including caffeic acid, rutin, and hyperoside. The extract displayed significant antimicrobial effects against H. pylori, with consistent MIC and MBC values of 3.70 ± 0.09 mg/mL. AOME reduced cell viability in all gastric cancer cell in a dose and time-dependent manner. Morphological analyses revealed significant ultrastructural changes in all tumor cells lines, suggesting the occurrence of cellular apoptosis. Conclusions: This study demonstrated that AOME possesses antimicrobial activity against H. pylori and potent antineoplastic properties in gastric cancer cell lines. AOME holds promise as a natural resource for innovative nutraceutical approaches in gastric cancer management. Further research and in vivo studies are warranted to validate its potential clinical applications.
REVIEW | doi:10.20944/preprints202307.0111.v1
Subject: Medicine And Pharmacology, Surgery Keywords: tumor response grade (TRG); gastric cancer; RECIST; tumor regression score
Online: 3 July 2023 (14:25:48 CEST)
Gastric cancer is among the top 5 causes of cancer-related death worldwide. Preoperative chemotherapy has been established as an option in patients with locally advanced gastric cancer. However, chemotherapy yields variable results, owing to the cellular and molecular heterogeneity of this disease. Identifying patients who did or did not respond to preoperative therapy can allow clinicians to alter treatment modalities and provide important information related to prognostication. Pathologic response to preoperative therapies, called Tumor Response Grade (TRG), has been evaluated to quantify treatment response. Multiple systems for TRG have been established. However, literature has demonstrated inconsistent results for TGR systems and prognosis, possibly due to variability in interpretation of tumor response between systems and interobserver variability. Radiographic response to preoperative therapies using RECIST 1.1 criteria and endoscopically-assessed tumor response have demonstrated association with survival; however their use in gastric cancer remains challenging given the inability to accurately and consistently identify and measure the tumor, especially in the setting of neoadjuvant therapy where treatment-related changes can obscure the gastric wall layers. This review is focused on summarizing the available literature related to evaluating TRG in gastric cancer, as well as providing a brief overview on the use of radiographic and endoscopic methods to assess response to preoperative therapies. Lastly, we outline future directions regarding the use of a universal TRG system to guide care and assist with prognosis.
ARTICLE | doi:10.20944/preprints202108.0418.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: CAST; Lgr5; WNT; Gastric cancer; Machine assisted searching; macrophage
Online: 20 August 2021 (14:00:27 CEST)
Background: Gastric cancer (GC) is one of the leading malignancy diseases worldwide, especially in Asian. CAST is a potential oncogene in GC carcinogenesis process. The character of macrophage infiltration in GC microenvironment was also unaddressed. Methods: We first applied machine searching in gene candidate evaluation of GC. CAST expression was analyzed via the Human Protein Atlas (HPA) and Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database. Protein-protein interaction (PPI) network was downloaded from STRING. We investigated the impact of CAST on clinical prognosis using Kaplan-Meier plotter. The correlations between CAST and Lgr5 and macrophage infiltration in GC was surveyed via TIMER 2.0. Finally, GeneMANIA was also used to evaluate the possible functional linkage between genes. Results: After machine-assisted searching, CAST expression was found signicant difference in the overall survival of GC patients. STRING revealed CAST related proteomics and transcriptomics associations, mainly about CAPN family. Moreover, CAST significantly impacts the prognosis of GC from other datasets validation. Notably, high CAST expression was correlated with worse overall survival in GC patients (hazard ratio = 1.59; logrank P = 9.4 x 10-8). CAST and Lgr5 expressions were both positively correlated with WNT 2 and WNT 2B. Among GC patients in several datasets, CAST and macrophage infiltration evaluated together showed no obvious trend toward poor clinical overall survival. Conclusion: CAST plays an important role in GC clinical prognosis and is associated with WNT 2/WNT 2B/Lgr5. Our study denmostrated that CAST in GC overall survival is regulated by macrophage infiltration.
REVIEW | doi:10.20944/preprints202107.0612.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Gastric cancer; natural products; autophagy; apoptosis; angiogenesis; metastasis; chemo-resistance.
Online: 27 July 2021 (22:20:18 CEST)
Gastric cancer, also known as stomach cancer, is a cancer which develops from the lining of the stomach. Accumulated evidences and epidemiological studies have been indicated that natural products play an important role in gastric cancer prevention and treatment, although its mechanism of action did not elucidate yet. Particularly, experimental studies have been showed that natural products displayed a protective effect against gastric cancer via numerous molecular mechanisms such as suppression of cell metastasis, anti-angiogenesis, inhibition of cell proliferation, induction of apoptosis, and modulation of autophagy. Although chemotherapy remains the standard treatment for advanced gastric cancer along with surgery, radiation therapy, hormone therapy and immunotherapy, but its adverse side effects including neutropenia, stomatitis, mucositis, diarrhea, nausea, and emesis are well documented. Additionally, intake of naturally occurring phytochemicals could increase the efficacy of gastric chemotherapy and chemotherapeutics resistance. However, natural product structural stability and powerful bioactivity are important to develop novel treatments for gastric cancer that may minimize such adverse effects. Therefore, the purpose of this review is to summarize the potential therapeutic effects of natural products on prevention and treatment of gastric cancer with intensive molecular mechanisms of action, bioavailability, and safety efficacy.
ARTICLE | doi:10.20944/preprints202310.1204.v1
Subject: Medicine And Pharmacology, Other Keywords: gastric cancer; Nivolumab; immune response; tumor microenvironment; RNA-Seq
Online: 19 October 2023 (03:29:48 CEST)
Background: We investigated the tumor immune response in gastric cancer patients receiving third line nivolumab monotherapy to identify immune-related biomarkers for better patient se-lection. Methods: Nineteen patients (10 males, median age 67 years) who received nivolumab as a third or later line therapy were enrolled. We analyzed the tumor immune response in durable clinical benefit (DCB) and non-DCB patients. Pre-treatment and early-on-treatment tumor transcriptomes were examined, and gene expression profiles, immunograms, and T cell receptor (TCR) repertoire were analyzed. Results: DCB was observed in 15.8% of patients, with comparable secondary endpoints (ORR, OS, PFS) to previous trials. Individual immunograms showed no significant changes before and ear-ly-on-treatment, nor consistent alterations among DCB cases. The intratumoral immune response was suppressed by previous treatments in most third or later line nivolumab recipients. TCR repertoire analysis revealed newly emerged clonotypes in on-treatment tumors, but clonal re-placement did not impact efficacy. High T cells/Tregs ratios and a low UV radiation response gene signature were linked to DCB and treatment response. Conclusions: This study emphasizes the tumor immune response's importance in nivolumab ef-ficacy for gastric cancer. High T cells/Tregs ratios and specific gene expression signatures show promise as potential biomarkers for treatment response. Larger cohort validation is crucial to optimize immune checkpoint inhibitors in gastric cancer treatment.
ARTICLE | doi:10.20944/preprints202303.0276.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: tRNA fragments; extracellular vesicles; Gastric Cancer; NGS data repurposing; cancer biomarkers
Online: 15 March 2023 (09:18:23 CET)
Transfer RNA fragments (tRFs) have gene silencing effects similarly to miRNAs, can be sorted into extracellular vesicles (EVs) and are emerging as potential circulating biomarkers for cancer diagnosis. We aimed at analyzing the expression of tRFs in gastric cancer (GC) and understanding their potential as biomarkers. We explored miRNA datasets from gastric tumors and normal adjacent tissues (NAT) from TCGA repository, and proprietary 3D-cultured GC cell lines and corresponding EVs, in order to identify differentially represented tRFs using MINTmap and R/Bioconductor packages. Selected tRFs were validated in patient-derived EVs. We found 613 Differentially Expressed (DE)-tRFs in the TCGA dataset, of which 19 were concomitantly upregulated in TCGA gastric tumors and present in 3D-cells and EVs, but barely expressed in NAT. Moreover, 20 tRFs were expressed in 3D-cells and EVs and downregulated in TCGA gastric tumors. Of these 39 DE-tRFs, 9 tRFs were also detected in patient-derived EVs. Interestingly, the targets of these 9 tRFs affect neutrophil activation and degranulation, cadherin binding, focal adhesion and cell-substrate junction, highlighting these pathways as major targets of EV-mediated crosstalk with the tumor microenvironment. Furthermore, as they are present in four distinct GC datasets and can be detected even in low quality patient-EV derived samples, they hold promise as GC biomarkers. By repurposing already available NGS data, we could identify and cross-validate a set of tRFs holding potential as GC diagnosis biomarkers.
ARTICLE | doi:10.20944/preprints202306.1491.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: epithelial–mesenchymal transition (EMT); Gastric cancer; lipopolysaccharides (LPS); Nivolumab; TGF-β
Online: 21 June 2023 (07:28:13 CEST)
Lipopolysaccharides are a type of polysaccharide mainly present in the bacterial outer membrane of Gram-negative bacteria. Recent studies have revealed that lipopolysaccharides contribute to the immune response of the host by functioning as a cancer antigen. We retrospectively recruited 198 patients with gastric cancer who underwent surgery. The presence of lipopolysaccharides was determined using immunohistochemical staining, with the intensity score indicating positivity. The relationship between lipopolysaccharides and CD8, PD-L1, TGFBI (a representative downstream gene of TGF-β signaling), E-cadherin, and claudin-4 (epithelial–mesenchymal transition markers) was also investigated. Thereafter, we identified 20 patients with advanced gastric cancer receiving nivolumab and investigated the relationship between lipopolysaccharides and nivolumab sensitivity. After staining for lipopolysaccharides in the nucleus of cancer cells, 150 negative (75.8%) and 48 positive cases (24.2%) were found. The lipopolysaccharide-positive group showed increased cancer stromal TGFBI expression (p < 0.0001) and PD-L1 expression in cancer cells (p = 0.0029). Lipopolysaccharide positivity was significantly correlated with decreased E-cadherin expression (p = 0.0055) and claudin-4 expression (p = 0.029); however, no significant correlation was found between lipopolysaccharide expression and overall survival rate (p = 0.71). Among cases receiving nivolumab, the lipopolysaccharide-negative and -positive groups had a disease control rate of 66.7% and 11.8%, respectively (p = 0.049). Lipopolysaccharide positivity was associated with TGF-β signaling and epithelial–mesenchymal transition and was considered to promote therapeutic resistance to nivolumab.
REVIEW | doi:10.20944/preprints202307.0306.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Advanced and metastatic gastric cancer; first-line systemic treatment; systematic review
Online: 6 July 2023 (02:24:35 CEST)
Globally, gastric cancer is a major cause of cancer mortality, with a 5-year survival rate of 32% for locally advanced and metastatic gastric cancer. This systematic literature review summarized the clinical, safety, and humanistic outcomes associated with systemic regimens given as first line therapy for locally advanced and metastatic gastric cancer. The search included articles published in English in PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and the American Society of Clinical Oncology meeting library, from inception to April 2022. Phase II and III randomized controlled trials conducted among western populations diagnosed with stage III and IV locally advanced and metastatic gastric cancer were included. Two investigators independently reviewed the studies, conducted data extraction, and assessed risk of bias in accordance with PRISMA guidelines. Twenty-four randomized controlled trials totaling 8,705 patients were included. Median overall survival ranged from 5.0-13.1 months, median progression-free survival ranged from 2.0-7.7 months, and objective response ranged from 13.0-64.1%. Two studies reported higher quality of life outcomes. Grade 3 and 4 adverse events were reported in most studies. Improvement in clinical outcomes can be seen in recently published randomized controlled trials for locally advanced and metastatic gastric cancer.
ARTICLE | doi:10.20944/preprints202105.0729.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Gastric cancer; Cyclin-dependent protein kinase; Cluster of differentiation (CD) 47; Prognosis
Online: 31 May 2021 (10:13:20 CEST)
Objective: To investigate the protein expression levels of cyclin‑dependent kinase subunit 2 (CKS2) and cluster of differentiation (CD) 47 in gastric cancer (GC) and their clinical significances. Methods: A total of 126 GC patients who underwent radical resection were selected as study subjects. Additionally, 32 patients with benign gastric tumor, 42 patients with low-grade intraepithelial neoplasia (LGIEN), and 49 patients with high-grade intraepithelial neoplasia (HGIEN) who underwent surgery were selected as the control groups. Immunohistochemistry was used to detect the expression of CKS2 and CD47 in surgical specimens. We statistically analyzed the clinical significance of the expression of the two factors. Results: (1) The positivity rates for CKS2 in benign gastric tumor tissue, LGIEN tissue, HGIEN tissue, and GC tissue gradually increased, i.e., 6.3% (2/32), 30.9% (13/42), 38.8% (19/49), and 60.3% (76/126), respectively, and the positivity rates for CD47 were 18.8% (6/32), 38.1% (16/42), 46.9% (23/49), and 65.9% (83/126), respectively. (2) High expression of CKS2 and CD47 were associated with tumor diameter, Lauren classification, number of lymph node metastases, and TNM stage. In addition, the immunohistochemical scores for CKS2 and CD47 were positively correlated (r=0.625, P=0.000). (3) The median follow-up time of 126 patients was 46.5 months, and the overall survival rate was 40.5% (51/126). Survival analysis showed that compared with that in the CKS2 (-) group, the overall survival rate for patients in the CKS2 (+) group was significantly worse (25.0% vs 64.0%, 2=15.67, P=0.000) and that compared with the CD47 (-) group, the CD47 (+) group had significantly worse overall survival (30.1% vs 60.5%, 2=15.67, P=0.000). (4) The overall survival rates of CKS2(+)CD47(+) group, CKS2(+)CD47(-) group, CKS2(-)CD47(+) group, and CKS2 (-)CD47 (-) group were 20.0%(13/65), 58.3%(7/12), 57.1%(8/14), 65.7% (23/35), respectively, the prognosis of patients in CKS2(+)CD47(+) group was significantly poor. Conclusion: High expression levels of CKS2 and CD47 were closely related to the occurrence of GC and can be used as independent risk factors to assess the prognosis of patients.
REVIEW | doi:10.20944/preprints202304.0555.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Gastric Cancer; Helicobacter pylori; cag Pathogenicity Island; Cytotoxin-Associated Gene A; Oncoprotein; Vacuolating Toxin A; Immune Evasion
Online: 19 April 2023 (07:14:39 CEST)
Gastric cancer is a challenging public health concern worldwide and remains a leading cause of cancer-related mortality. The primary risk factor implicated in gastric cancer development is infection with Helicobacter pylori. H. pylori induces chronic inflammation affecting the gastric epithelium, which can lead to DNA damage and promotion of precancerous lesions. Disease manifestations associated with H. pylori are attributed to virulence factors with multiple activities and its capacity to subvert host immunity. One of the most significant H. pylori virulence determinants is the cagPAI gene cluster, which encodes a type IV secretion system and the CagA toxin. This secretion system allows H. pylori to inject the CagA oncoprotein into host cells, causing multiple cellular perturbations. Despite the high prevalence of H. pylori infection, only a small percentage of affected individuals develop significant clinical outcomes, while most remain asymptomatic. Therefore, understanding how H. pylori triggers carcinogenesis and its immune evasion mechanisms is critical in preventing gastric cancer and miti-gating the burden of this life-threatening disease. This review aims to provide an overview of our current under-standing of H. pylori infection, its association with gastric cancer and other gastric diseases, and how it subverts the host immune system to establish persistent infection.
ARTICLE | doi:10.20944/preprints202306.1685.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Gastric cancer; H. pylori; activity of neutrophilic granulocytes; oxidative stress.
Online: 23 June 2023 (12:54:01 CEST)
Aim. To study the processes of lipid peroxidation and the activity of antioxidant defense enzymes depending on the chemiluminescent activity of neutrophilic granulocytes in patients with gastric cancer associated with H. pylori infection, depending on the stage. Materials and methods. 39 patients with stage I-II gastric cancer and 30 patients with stage III-IV gastric cancer were examined. The study of the chemiluminescent activity of neutrophilic granulocytes was carried out, the parameters of the lipid peroxidation system and antioxidant protection in plasma were determined using the spectrophotometric method. Statistical data processing was performed using the Statistica 7.0 software package (StatSoft, USA). Results. In patients with gastric cancer associated with H. pylori infection, regardless of stage, the proportion of neutrophilic granulocytes with normal activity does not exceed 1/3 of the total number of patients, the remaining 2/3 of patients have an altered chemiluminescent activity of neutrophilic granulocytes: in patients with gastric cancer by I -II stage of the disease, the majority revealed a reduced function of neutrophilic granulocytes, and in patients with gastric cancer stage III-IV of the disease, the majority showed increased chemiluminescent activity of neutrophilic granulocytes. In all patients with gastric cancer associated with H. pylori infection, regardless of the stage of the disease, an increase in lipid peroxidation processes with activation of antioxidant defense enzymes was detected. Conclusion. In all patients with gastric cancer associated with H. pylori infection, regardless of the stage of the disease, an increase in lipid peroxidation processes with activation of antioxidant defense enzymes was detected. At the same time, there are no statistically significant differences between the indicators of the system lipid peroxidation - antioxidant protection depending on the stage of gastric cancer and the chemiluminescent activity of neutrophilic granulocytes, which probably indicates that all reactive oxygen species produced by neutrophilic granulocytes in the respiratory burst are consumed locally, minimally affecting the development of oxidative stress in the blood plasma.
ARTICLE | doi:10.20944/preprints202007.0484.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: Gastric cancer; Submucosal invasion; Intestinal stem cell; Cancer stem cell; Prognosis
Online: 21 July 2020 (12:34:02 CEST)
Submucosal invasion is a critical step in gastric cancer (GC) progression, which greatly enhances metastasis risk. Cancer stem cells are responsible for invasion, metastasis, and tumor growth. To identify stem cell-related markers associated with submucosal invasion in GCs, we investigated the expression of candidate cancer stem cell (CSC) markers (CD133, CD44, and ALDH1A) and intestinal stem cell (ISC) markers (EPHB2, OLFM4, and LGR5) in early GCs with submucosal invasion. Remarkably, expression of all ISC markers and CD133 was frequently confined to the basal area of the lamina propria (basal pattern) in mucosal cancer. The proportion of stem cell marker-positive cells substantially increased during submucosal invasion. Given that ISC markers are restricted to the crypt base of the normal intestinal mucosa, these findings suggest that many early GCs may retain hierarchical characteristics. CD44 expression showed a focal pattern, ALDH1A was predominantly expressed diffusely, and there was no expansion of CD44 or ALDH1A expression in the submucosal cancer cells. RSPO2 from muscularis mucosa seem to be partly responsible for the increased expression of ISC markers in GC cells at the basal areas. We also found that ISC markers were correlated with CDX2 expression in GCs, indicating that ISC markers are involved in the intestinal differentiation in GCs. Interestingly, ISC markers (EPHB2 and OLFM4) and CD133 showed a positive impact on clinical outcomes. In particular, the prognostic value of EPHB2 was significant for intestinal-type GCs in a multivariate analysis. In summary, ISC markers and CD133 showed a basal distribution pattern along with enhanced expression in submucosal invading cells in early GCs. EPHB2 was an independent prognostic marker in intestinal-type GCs.
ARTICLE | doi:10.20944/preprints202306.1947.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: autoimmune thyroid disease; Helicobacter pylori; gastric atrophy; gastric metaplasia; gastric dysplasia; Hashimoto's thyroiditis; Grave's disease
Online: 28 June 2023 (04:54:20 CEST)
Background. Helicobacter pylori infection has long been suspected to increase the risk of thyroid diseases but evidence from literature is conflicting. In a cohort of patients from Northern Sardinia, Italy, who underwent upper endoscopy, we investigated the association between current and long-lasting Helicobacter pylori infection and thyroid disease, both autoimmune and non-autoimmune, by adjusting for potential confounds. Methods. By using multivariable logistic regression we analyzed a cohort of 8490 adults aged 6–93 years: 730 were diagnosed with autoimmune thyroid disease (AITD) and 448 with nonautoimmune thyroid diseases. Results. We found a significant association between H. pylori long-lasting infection and AITD independently of age, sex, body mass index, smoke, hypertension and dyslipidemia (OR 1.42; 95%CI 1.20‒1.66) while the opposite was found regarding current infection (OR 0.75; 95%CI 0.63‒0.89). Current infection was not significantly associated to non-autoimmune thyroiditis. Conclusions. H. pylori infection is an independent risk factor for AITD in the population of Northern Sardinia, therefore it is advisable to eradicate the pathogen in subjects at risk of AITD.
ARTICLE | doi:10.20944/preprints202311.1185.v1
Subject: Medicine And Pharmacology, Other Keywords: Morus alba L.; gastric cancer; HGC27 cells; cytotoxic activities
Online: 21 November 2023 (10:26:25 CET)
Three new compounds (1, 11 and 12), together with 32 known ones, were isolated from the root bark of Morus alba L. using various chromatographic methods. The structures of the undescribed compounds were elucidated based on 1D, 2D NMR and HRESIMS data analysis, while the known ones were identified by comparison of their spectroscopic data with those reported in the literature. All the isolates were evaluated for their cytotoxic activities against human gastric cancer HGC27 cells by CCK-8 assay. Among them, compounds 5, 8, 10 and 30 exhibited cytotoxic activities on HGC27 cells with IC50 values of 10.24 ± 0.89 μM, 28.94 ± 0.72 μM, 6.08 ± 0.34 μM and 33.76 ± 2.64 μM, respectively. Furthermore, compound 10 was confirmed to reduce proliferation ability, increase apoptosis rate and inhibit cell migration pathway by annexin V/PI double staining experiment, transwell experiment and western blot analysis.
ARTICLE | doi:10.20944/preprints202306.1516.v1
Subject: Medicine And Pharmacology, Anesthesiology And Pain Medicine Keywords: Pulmonary aspiration; gastric ultrasound; antrum; gastric volume; elective surgery
Online: 21 June 2023 (09:54:17 CEST)
Pulmonary aspiration is a serious anaesthetic complication with morbidity and up to 9% of all anaesthesia-related mortality. Aspiration risk is especially focused on fastening time. We aimed to evaluate the prevalence of 'risky stomach' defined by ultrasound imagine of solid contents and/or calculated gastric fluid volume >1.25 mL/kg in elective surgery also comparing this definition with the 0-2 qualitative rating scale used for "empty/risky stomach". This prospective study has 97 patients aged 2-18. Ultrasonographic evaluations of the gastric antrum content is scaled with qualitative assessment in supine and right lateral decubitus (RLD) position. Gastric volume was calculated. In our study, stomach content and volume were evaluated by ultrasound in 97% of children and 5.2% had Grade 2 antrum. In RLD position, antral CSA was 2.36 cm², and the median gastric volume was 0.46 mL/kg. In patients with grade 0 antrum has moderate and positive correlation between antral CSA and BMI, and strong and positive correlation between antral CSA and age like grade 1 antrum. We showed that 0.1%-4.7% of elective children had gastric fluid volumes of >1.25 mL/kg as "risky stomach". Ultrasound for gastric contents could be used routine practice to determine pulmonary aspiration risk in emergency and elective procedures.
ARTICLE | doi:10.20944/preprints202306.1178.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: gastric cancer; molecular classification; EBER; MMR; E-cadherin; beta-catenin; p53; Her2; PD-L1; Claudin18.2
Online: 16 June 2023 (05:46:59 CEST)
Background and Objectives: Gastric cancer (GC) is one of the most commonly diagnosed cancer and the fourth cause of cancer death worldwide. Personalised treatment improves GC outcomes. A molecular classification is needed to choose the appropriate therapy. A classification that uses on-slide biomarkers and formalin-fixed and paraffin-embedded (FFPE) tissue is preferable to comprehensive genomic analysis. In 2016, Setia et al. proposed an on-slide classification, however this is not in widespread use. We propose a modification of this classification that has six subgroups: GC associated with Epstein-Barr virus (GC EBV+), GC with mismatch repair deficiency (GC dMMR), GC with epithelial-mesenchymal transformation (GC EMT), GC with functional loss of p53 due to mutation (GC p53m), CG with intact p53 (GC p53wt) and GC not otherwise specified (GC NOS). This classification also has provision for biomarkers for current or emerging targeted therapies (Her2, PD-L1 and Claudin18.2). Here we assess the implementation and feasibility of this inclusive working classification. Materials and Methods: We constructed a tissue microarray library from a cohort of 79 resection cases from FFPE tissue archives. We used a restricted panel of on-slide markers (EBER, MMR, E-cadherin, beta-catenin and p53), defined their interpretation algorithms, and assigned each case to a specific molecular subtype. Results: GC EBV(+) cases were 6%, GC dMMR cases were 20%, GC EMT cases were 14%, GC p53m cases were 23%, GC p53wt cases were 29% and GC NOS cases were 8%. Conclusions: This working classification uses markers that are widely available in Histopathology and are easy to interpret. A diagnostic subgroup is obtained for 92% of the cases. The proportion of cases in each subgroup is in keeping with other published series. Widescale implementation appears feasible. A study using endoscopic biopsies is warranted.
ARTICLE | doi:10.20944/preprints202204.0312.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Tensional homeostasis; Traction microscopy; Gastric cancer cells; E-cadherin mutations; Extra-cellular matrix proteins
Online: 30 April 2022 (05:18:13 CEST)
In epithelia, breakdown of tensional homeostasis is closely associated with E-cadherin dysfunction and disruption of tissue function and integrity. In this study, we investigated the effect of E-cadherin mutations affecting distinct protein domains on tensional homeostasis of gastric cancer cells. We used micropattern traction microscopy to measure temporal fluctuations of cellular traction forces in AGS cells transfected with the wild-type E-cadherin or with variants affecting the extracellular, the juxtamembrane, and the intracellular domains of the protein. We focused on the dynamic aspect of tensional homeostasis, namely the ability of cells to maintain a consistent level of tension, with low temporal variability around a set point. Cells were cultured on hydrogels micropatterned with different extracellular matrix (ECM) proteins to test whether the ECM adhesion impacts cell behavior. A combination of Fibronectin and Vitronectin was used as a substrate that promotes the adhesive ability of E-cadherin dysfunctional cells, whereas Collagen VI was used to test an unfavorable ECM condition. Our results showed that mutations affecting distinct E-cadherin domains influenced differently cell tensional homeostasis, and pinpointed the juxtamembrane and intracellular regions of E-cadherin as the key players in this process. Furthermore, Fibronectin and Vitronectin might modulate cancer cell behavior towards tensional homeostasis.
ARTICLE | doi:10.20944/preprints202304.0791.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Helicobacter pylori-uninfected gastric cancer; gastric adenocarcinoma of foveolar type; raspberry-shaped gastric lesion; gastric adenocarcinoma of fundic-gland type; gastric adenocarcinoma of fundic-gland mucosa type; hyperplastic polyp; proton pump inhibitor-related lesion; early gastric cancer.
Online: 23 April 2023 (08:12:59 CEST)
Objectives: We aimed to clarify the endoscopic and clinicopathological features of raspberry-shaped gastric lesions (RSGLs) and to establish an endoscopic diagnostic algorithm for RSGLs. Methods: We collected RSGLs from an endoscopic database at our hospital between May 2009 and August 2021. All RSGLs were histopathologically classified and compared based on their endoscopic and clinicopathological characteristics. Results: Sixty-five RSGLs in 54 patients were classified into five histopathological types: gastric adenocarcinoma of foveolar type (GA-FV, n = 43), gastric adenocarcinoma of fundic-gland type (GA-FG, n = 2), gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM, n = 4), hyperplastic polyp (HP, n = 12), and proton pump inhibitor-related lesion (PPI-L, n = 4). All RSGLs exhibited polygonal or curved marginal crypt epithelium (MCE). GA-FV lesions had homogenously reddish (95%) and irregular microvascular (MV) pattern (91%). GA-FG lesions were heterogeneously reddish with a submucosal tumor shape (100%) and had a regular MV pattern (50%). GA-FGM lesions were homogenously reddish (75%) and occasionally had a submucosal tumor shape (50%) with an irregular MV pattern (75%). HP and PPI-L were homogeneously reddish (93%), with linear or dotted MCE (81%) and a regular MV pattern (100%). Conclusion: Our diagnostic algorithm for RSGLs constructed using endoscopic features might be useful for the endoscopic differential diagnosis of RSGLs.
REVIEW | doi:10.20944/preprints202306.0932.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: gastric cancer; HER2; immunotherapy; PD-1/PD-L1; antibody-drug conjugate; chemotherapy; trastuzumab; novel therapies; clinical trials
Online: 13 June 2023 (11:15:24 CEST)
Gastric cancer is an aggressive disease with increasing global incidence in recent years. Human epidermal growth receptor 2 (HER2) is overexpressed in approximately 10-20% of gastric cancers. The implementation of targeted therapy against HER2 as part of the standard of care treatment in metastatic disease has improved the prognosis of this subset of patients. However, gastric cancer still has high mortality rates and urgently requires new treatment strategies. The combination of immunotherapy with HER2-targeted therapies has shown synergistic effects in preclinical models, being the rationale behind exploring this combination in clinical trials in locally advanced and metastatic settings. Additionally, the irruption of antibody-drug conjugates and other novel HER2-targeted agents has led to the development of numerous clinical trials showing promising results. This review presents the molecular mechanisms supporting the use of HER2-targeted drugs in combination with immunotherapy and provides an overview of the therapeutic scenario of HER2-positive disease. We focus on the role of immunotherapy but also summarize emerging therapies and combinations under clinical research that may change the standard treatment in HER-2 positive disease in the future.
ARTICLE | doi:10.20944/preprints202110.0198.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: BRCA1; cancer stem cell; cell cycle; epithelial-mesenchymal transition; DNA damage response; gastric cancer; molecular network
Online: 13 October 2021 (11:06:51 CEST)
Epithelial-mesenchymal transition (EMT) networks are essential in acquiring the drug resistance and cancer malignant features in cancer stem cells (CSCs). In this regard, gene expression profiles in diffuse- and intestinal-type gastric cancer (GC) have been analyzed to reveal the network pathways in EMT and CSCs, since the diffuse-type GC has much more mesenchymal features than intestinal-type GC that has the intestinal features. The study results revealed that the activation state of several canonical pathways related to cell cycle regulation was altered. The canonical pathway on Cell cycle: G1/S checkpoint regulation was activated in diffuse-type GC, and canonical pathways on Cell cycle control of chromosomal replication and Cyclins and cell cycle regulation were activated in intestinal-type GC. Canonical pathway related to Role of BRCA1 in DNA damage response was activated in intestinal-type GC, where BRCA1, which is related to G1/S phase transition was up-regulated in intestinal-type GC. Several microRNAs (miRNAs), including mir-10, mir-17, mir-19, mir-194, mir-224, mir-25, mir-34, mir-451, and mir-605, were identified to have direct relationships of RNA-RNA interaction in Cell cycle: G1/S checkpoint regulation pathway. Additionally, cell cycle regulation may be altered in EMT conditions. The alterations in activation states of the pathways related to cell cycle regulation in diffuse- and intestinal-type GC would indicate the significance of cell cycle regulation in EMT.
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Colorectal Cancer Cells; Gastric Cancer Cells; Cholangiocarcinoma Cells; Hepatocarcinoma Cells; Exosomes; FZD 10 protein; FZD10-mRNA; FZD10-mRNA Silenced Cells; Cell Proliferation
Online: 9 July 2019 (14:19:22 CEST)
Extracellular vesicles (EVs) are involved in intercellular communication during carcinogenesis and cancer cells are able to secrete EVs, in particular exosomes containing molecules, that can be transferred to recipient cells to induce pathological processes and significant modifications, as metastasis, increase of proliferation and carcinogenesis evolution. FZD proteins, a family of receptors comprised in the Wnt signaling pathway, play an important role in carcinogenesis of gastroenteric tract. Here, a still unrecognized role of Frizzled 10 (FZD10) protein was identified. In particular, the presence of FZD10 and FZD10-mRNA in exosomes extracted from culture medium of the untreated colorectal, gastric, hepatic and cholangio cancer cell lines, was detected. A substantial reduction in the FZD10 and FZD10-mRNA level was achieved in FZD10-mRNA silenced cells and in their corresponding exosomes and, concomitantly a significant decrease in viability of the silenced cells compared to their respective controls was observed. Interestingly, the incubation of silenced cells with exosomes extracted from culture medium of the same untreated cells promoted a remarkable restoration of the cell viability and, also, of the FZD10 and FZD10-mRNA level, thus indicating that the FZD10 and FZD10-mRNA delivering exosomes may be potential messengers of cancer reactivation and play an active role in long-distance metastatization
ARTICLE | doi:10.20944/preprints202110.0297.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: gastric cancer; immunotherapy; immune checkpoint blockade (ICB); immune checkpoint inhibitors (ICI),; DNA repair gene signature (DRGS); prognostic biomarker; score system
Online: 20 October 2021 (22:47:19 CEST)
Gastric cancer is a heterogeneous group of diseases with only a fraction of patients responds to immunotherapy. The relationships between tumor DNA damage response, the immune system and immunotherapy have recently attracted attention. Accumulating evidence indicate that DNA repair landscape is a significant factor in driving response to immune checkpoint blockade (ICB) therapy. In this study, to explore new prognostic and predictive biomarkers for gastric cancer patients who are sensitive and responsible to immunotherapy, we developed a novel 15-DNA repair gene signature (DRGS) and its related scoring system and evaluated the efficiency of DRGS in discriminating different molecular and immune characteristics and therapeutic outcomes of gastric adenocarcinoma. The results showed that DRGS high score patients showed significantly better therapeutic outcomes compared to DRGS low score patients (P < 0.001). Integrated analysis of multi-omics data demonstrated that the patients with high DRGS score were characteristic of high levels of anti-tumor lymphocytes infiltration, tumor mutation burden (TMB) and PD-L1 expression, and these patients exhibited a longer overall survival and may benefit more from ICB therapy, as compared to the low-score patients. Therefore, the DRGS and its scoring system may have implications in tailoring immunotherapy in gastric cancers.
REVIEW | doi:10.20944/preprints202209.0096.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: EBV; EBV malignancies; EBV-associated gastric cancer (EBVaGC); Tumor microenvironment (TME); IFN-gamma; IDO1; H pylori; TAMs; M1; M2.
Online: 7 September 2022 (03:23:18 CEST)
Although most people are infected with Epstein-Barr Virus (EBV) during their lifetime, only a minority of them develop an EBV-associated malignancy. EBV acts in both direct and indirect ways to transform infected cells into tumor cells. There are multiple ways in which the EBV, host, and tumor environment interact to promote malignant transformation. This paper focuses on some of the mechanisms that EBV uses to transform the tumor microenvironment (TME) of EBV-associated gastric cancer (EBVaGC) for its benefit, including overexpression of IDO1, synergism between H pylori and EBV coinfection, and M1 to M2 switch. In this review, we expand on different modalities and combinatorial approaches to therapeutically target this mechanism.
ARTICLE | doi:10.20944/preprints202308.1724.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: claudin 6; gastric cancer; transcriptional regulation
Online: 24 August 2023 (07:14:00 CEST)
Aberrant expression of the tight junction protein claudin 6 (CLDN6) is a hallmark of gastric can-cer progression. Its expression is regulated by the transcription factor CREB. But in H. pylo-ri-induced gastric cancer there is no information regarding what transcription factors in-duce/upregulate the expression of CLDN6. We aimed to identify if CREB and YY1 regulate the expression of CLDN6 and the site where they bind to the promoter sequence. Bioinformatics analysis, H. pylori LPS, YY1 and CREB silencing, western blot, luciferase assays, and chromatin immunoprecipitation experiments were performed using the gastric adenocarcinoma cell line AGS. A gen reporter assay suggested that the initial 2000 bp contains the regulatory sequence as-sociated with CLDN6 transcription; the luciferase assay demonstrated three different regions with transcriptional activity, but the -901 to -1421 bp region displayed the maximal transcrip-tional activity in response to LPS. Fragment 1279-1421 showed CREB and surprisingly YY1 oc-cupancy. Sequential ChIP experiments confirmed that YY1 and CREB interact in the 1279-1421 region. Our results suggest that CLDN6 expression is regulated by the binding of YY1 and CREB in the 901-1421 enhancer in which a non-described interaction of YY1 with CREB was established in the 1279-1421 region.
ARTICLE | doi:10.20944/preprints201804.0307.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: gastric cancer; ramucirumab; paclitaxel; second line therapy; vascular endothelial growth factor receptor 2; targeted therapy; nutrition
Online: 24 April 2018 (06:01:56 CEST)
The RAINBOW Phase III study established the efficacy of the combination of paclitaxel and ramucirumab, a monoclonal antibody targeting VEGF receptor-2 (VEGF-R2), as second-line therapy. We retrospectively analyzed the data of patients treated with ramucirumab plus paclitaxel at our Institution to evaluate the impact of clinical heterogeneous figures on the efficacy and safety of this combination paclitaxel/ramucirumab in a real- life cohort of patients. After a median follow-up of 10.74 months, the median progression-free survival (PFS) was 5.8 months (95% CI: 3.04 - 5,63). Disease control rate (DCR) was 61% and the median duration of response (DOR) was 5.8 months. Median overall survival (OS) was 8.3 months. A trend toward better outcome was observed in HER2 positive patients. In multivariate analysis, nutritional status (p = 0.0001) and number of metastatic sites (p = 0.0266) resulted significantly related with longer PFS. Our analysis confirmed the efficacy and safety of the combination of ramucirumab with paclitaxel also in the real-life practice and the median PFS is significantly longer than that reported for Western population in previous studies. Subgroup analysis confirms the key-role of nutritional status as prognostic factor and suggests a possible interaction between EGF and angiogenesis pathways that deserves further investigations.
REVIEW | doi:10.20944/preprints202310.1620.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: gastric perforation; leak; suturing; clips; sponge; endovacuum
Online: 25 October 2023 (10:13:24 CEST)
Gastric perforations and leaks are significant complications that can arise from various gastrointestinal disorders and surgical interventions. Over the past decade, endoscopic techniques have emerged as effective method for managing these conditions. Furthermore, as endoscopic resection techniques have grown in popularity, the risk of acute and delayed perforations has also grown. This review aims to provide an in-depth analysis of the endoscopic management strategies employed in the management of gastric perforations and leaks. We will discuss the etiology, diagnostic modalities, and various endoscopic techniques utilized, and emerging trends in endoscopic management. Our attempt in writing this review paper is to educate and guide clinicians in making informed decisions when faced with gastric perforations and leaks.
ARTICLE | doi:10.20944/preprints202102.0445.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Iron; Vitamin D; Vitamin B12; Roux-en-Y gastric bypass; Sleeve gastrectomy; Adjustable gastric banding; nutritional deficiency; bariatric surgery
Online: 19 February 2021 (14:36:21 CET)
Long-term nutritional studies in subjects undergoing bariatric surgery that have assessed weight regain and nutritional deficiencies are few. In this study, we report data 8 years after surgery on weight loss, use of dietary supplements and deficit of micronutrients in a cohort of patients from five centres in central and northern Italy. The study group consisted of 52 subjects (age: 38.1±10.6 yrs, 42 females): 16 patients had Roux-en-Y gastric bypass (RYGB), 25 patients sleeve gastrectomy (LSG) and 11 subjects adjustable gastric banding (AGB). All three bariatric procedures led to sustained weight loss: average percentage excess weight loss, defined as weight loss divided by excess weight based on ideal body weight was 60.6%±32.3. 80.7% of subjects (72.7%, AGB; 76%, SG; 93.7%, RYGB) reported at least one nutritional deficiency: iron (F 64.3% vs. M 30%), vitamin B12 (F 16.6% vs. M 10%), calcium (F 33.3% vs. M 0%) and vitamin D (F 38.1% vs. M 60%). Average weight loss was constant in RYGB and SG subjects from the third year after surgery. Long-term nutritional deficiencies were greater than the general population among men for iron and among women for vitamin B12.
ARTICLE | doi:10.20944/preprints202305.0198.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: gastric fluid; urine; metabolite; GC-MS; prematurity; survival
Online: 4 May 2023 (05:21:26 CEST)
Prediction of survival in very preterm infants is very important in terms of clinical medicine and parent counseling. In this prospective study involving 96 very preterm infants, we evaluated whether metabolomic analysis of gastric fluid and urine samples obtained soon after birth could predict survival on days of life (DOL) 3 and 15 as well as overall survival up to hospital discharge. Gas chromatography-mass spectrometry (GC-MS) profiling was used. Uni- and multivariate statistical analyses were carried out to evaluate significant metabolites and their prognostic value. Differences in several metabolites were identified between survivors and non-survivors at the time-points of the study. Binary logistic regression showed that certain metabolites in the gastric fluid including arabitol as well as succinic, erythronic and threonic acids was associated with DOL 15 and overall survival. Gastric glyceric acid was also associated with DOL 15 survival. Urine glyceric acid could predict survival on DOL 3 and overall survival. In conclusion, non-surviving preterm infants showed a different metabolic profile compared survivors showing a significant discrimination with the use of GC-MS-based gastric fluid and urine analysis. Results of this study support the usefulness of metabolomics in developing survival biomarkers in very preterm infants.
ARTICLE | doi:10.20944/preprints202208.0080.v1
Subject: Computer Science And Mathematics, Mathematical And Computational Biology Keywords: gastric cancer; deep learning; digital pathology; lymph node metastasis
Online: 3 August 2022 (08:48:02 CEST)
Histologically poor differentiation is associated with lymph node metastasis. Thus, pathological evaluation of biopsy specimens is crucial when treating stomach cancers. Deep learning of WSIs is challenging because the images are enormous. Given the computing limitations, patch-level supervised learning methods have been proposed. However, valuable information is lost when dividing WSIs into smaller patches. Another drawback is the need for pixel-level annotation by a pathologist. It is acceptable to differentiate, i.e., grade, gastric cancer at the holistic tissue level (i.e., under low magnification). We developed a weakly supervised learning technique for tissue-level gastric adenocarcinoma histological differentiation (well-to-moderately or poorly differentiated) and applied global reasoning to tissue-level features. The tissue-level AUROCs of the histological differentiation classifiers were 0.953, 0.969, and 0.943, respectively when data from five hospitals were subjected to threefold cross-validation. Comparison of the Grad-CAM heatmaps of the trained classifier and the pathologists’ annotations confirmed that our weakly supervised model exhibited performed well.
ARTICLE | doi:10.20944/preprints202310.1209.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: stomach; early gastric cancer; gastric adenoma; metachronous cancer; cumulative incidence; en-doscopic resection; endoscopic submucosal dissection; Helicobacter pylori; spontaneous eradica-tion; intestinal metaplasia
Online: 19 October 2023 (10:45:59 CEST)
Background: Although endoscopic submucosal dissection (ESD) can provide a high rate of curative resection, remaining gastric mucosa after ESD is at risk of metachronous recurrence. We investigated risk factors for metachronous superficial gastric epithelial neoplasms (MSGENs) following ESD. Methods: We conducted a retrospective cohort study including 369 patients with 382 lesions that underwent ESD for adenoma/early gastric cancer. The primary endpoint was to identify clinicopathological risk factors for the occurrence of MSGENs. The secondary endpoint was to evaluate the association of Helicobacter pylori (Hp) eradication with the MSGENs. Results: Twenty-seven MSGENs were occurred. The subjects were divided into MSGEN and not-MSGEN groups. There was a significantly higher frequency of histological intestinal metaplasia (HIM) and initial neoplasm location in upper or middle part (INUM) in the MSGEN group. The HIM group and INUM group had significantly higher cumulative incidence of MSGENs. We compared the 27 patients of MSGEN group and 27 patients of matched not-MSGEN (Mnot-MSGEN) group that was matched to the MSGEN group for variables including HIM and INUM. There was a significantly higher frequency of Hp spontaneous eradication in the MSGEN group. Conclusion: HIM, INUM and Hp spontaneous eradication may be clinicopathological risk factors for developing MSGENs after ESD.
ARTICLE | doi:10.20944/preprints202305.0995.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: CD44 variant 8; monoclonal antibody; gastric cancer; flow cytometry; immunohistochemistry
Online: 15 May 2023 (07:41:36 CEST)
Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. GC with peritoneal metastasis exhibits a poor prognosis due to the lack of diagnostic biomarkers and effective therapy. A comprehensive analysis of malignant ascites identified the genomic alterations and significant amplifications of cancer driver genes, including CD44. CD44 and its splicing variants are overexpressed in tumors, and play crucial roles in the acquisition of invasiveness, stemness, and resistance to treatments. Therefore, the development of CD44-targeting monoclonal antibodies (mAbs) is important for GC diagnosis and therapy. In this study, we immunized mice with CD44v3–10-overexpressed PANC-1 cells and established several dozens of clones that produce anti-CD44v3–10 mAbs. One of the clones (C44Mab-94; IgG1, kappa) recognized the variant-8-encoded region and peptide, indicating that C44Mab-94 is a specific mAb for CD44v8. Furthermore, C44Mab-94 could recognize CHO/CD44v3–10 cells, oral squamous cell carcinoma cell line (HSC-3), or GC cell lines (MKN45 and NUGC-4) in flow cytometric analyses. C44Mab-94 could detect the exogenous CD44v3–10 and endogenous CD44v8 in western blotting and stained the formalin-fixed paraffin-embedded gastric cancer cells in immunohistochemistry. These results indicate that C44Mab-94 is useful for detecting CD44v8 in various applications and is expected to be useful for the application of GC diagnosis and therapy.
ARTICLE | doi:10.20944/preprints202304.0837.v1
Subject: Biology And Life Sciences, Biophysics Keywords: Gastric signet ring cell carcinoma; lymph node metastases; LODDS; prognosis
Online: 24 April 2023 (09:00:47 CEST)
Background: The lymph nodes staging system can predict the prognosis of gastric signet ring cell carcinoma (SRCC), but the optimal system for early and advanced SRCC remains unknown. Methods: This study retrospectively analyzed 693 SRCC patients who underwent radical resection in the Department of Gastrointestinal Surgery, Harbin Medical University Cancer Hospital. The predicted performance of three lymph node staging systems, including pN staging, lymph node metastasis rate (LNR), and log odds of positive lymph nodes (LODDS), was compared using the receiver characteristic operating curve (ROC). The kaplan⁃meier method and the log⁃rank test analyze the overall survival of patients. The Cox risk regression model identifies independent risk factors associated with patient outcomes. The nomogram was made by R studio. Results: The 693 SRCC included 165 early SRCC and 528 advanced SRCC. ROC showed that LODDS had better predictive performance than pN and LNR in predicting prognosis regardless of early or advanced SRCC. LODDS can be used to predict the prognosis of early and advanced SRCC and was an independent risk factor associated with patient outcomes (P=0.002, P<0.001). Furthermore, the nomogram constructed by LODDS and clinicopathological features had good predictive performance. Conclusion: LODDS showed a clear prognostic superiority over both pN and LNR in early and advanced SRCC.
ARTICLE | doi:10.20944/preprints202201.0472.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: aspirin; pharmacometabolomic; nuclear magnetic resonance; spectroscopy; gastric toxicity; multivariate analysis
Online: 31 January 2022 (17:26:48 CET)
Background: Low-dose aspirin (LDA) is the backbone for secondary prevention of coronary artery disease, though limited by gastric toxicity. This study was aimed to identify novel metabolites that could predict LDA-induced gastric toxicity using pharmacometabolomics. Methods: Pre-dosed urine samples were collected from male Sprague-Dawley rats. The rats were treated with either LDA (10 mg/kg) or 1% methylcellulose (10 ml/kg) per oral for 28 days. The rats' stomachs were examined for gastric toxicity using a stereomicroscope. The urine samples were analyzed using a proton nuclear magnetic resonance spectroscopy. Metabolites were systematically identified by exploring established databases and multivariate analyses to identify the spectral pattern of metabolites related to LDA-induced gastric toxicity. Results: Treatment with LDA resulted in gastric toxicity in 20/32 rats (62.5%). The orthogonal projections to latent structures discriminant analysis (OPLS-DA) model displayed a goodness-of-fit (R2Y) value of 0.947, suggesting a near-perfect reproducibility, a goodness-of-prediction (Q2Y) of -0.185 with perfect sensitivity, specificity and accuracy (100%). Furthermore, the area under the receiver operating characteristic (AUROC) displayed was 1. The final OPLS-DA model had an R2Y value of 0.726 and Q2Y of 0.142 with sensitivity (100%), specificity (95.0%) and accuracy (96.9%). Citrate, hippurate, methylamine, trimethylamine N-oxide and alpha-keto-glutarate were identified as the possible metabolites implicated in the LDA-induced gastric toxicity. Conclusion: The study identiﬁed metabolic signatures that correlated with the development of a low dose Aspirin-induced gastric toxicity in rats. This pharmacometabolomic approach could further be validated to predict LDA-induced gastric toxicity in patients with coronary artery disease.
REVIEW | doi:10.20944/preprints202003.0251.v2
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: gastric acid suppressant; chemotherapy; tyrosine kinase inhibitors; proton pump inhibitors
Online: 31 March 2020 (03:40:46 CEST)
We performed a systematic review and meta-analysis to evaluate the role of gastric acid suppressant use on outcomes of tyrosine kinase inhibitors (TKIs) and oral chemotherapy. We identified all researches evaluating the effect of GAS use on patients receiving oral chemotherapy or TKIs for solid tumors. The pooled hazard ratios (HRs) and 95% confidence interval (95% CI) for overall survival (OS) and progression-free survival (PFS) were calculated with fixed-effects or random-effects model. The study population included n=16 retrospective studies and 372,418 patients. Series concerned gastrointestinal tract tumors (n=5 studies), renal cell carcinomas (RCC, n=3 studies), non-small cell lung cancers (NSCLC, n=5 studies), and soft tissue sarcomas or mixed histologies solid tumors in n=3 studies. The pooled HRs for OS and PFS were 1.31 (95% CI: 1.20–1.43; P<01) and 1.3 (95%CI 1.07-1.57; P<0.01) for GAS and no GAS users, respectively. Only studies of EGFR mutated NSCLC patients receiving TKIs and those with colorectal cancer receiving oral chemotherapy showed a significant correlation between GAS and poor survival. Our study supports the evidence of a possible negative impact of concomitant GAS therapy on survival outcomes of patients receiving oral anti-cancer drugs.
REVIEW | doi:10.20944/preprints202311.1665.v1
Subject: Medicine And Pharmacology, Surgery Keywords: Femoral Hernia; Amyand hernia; Hernia of Littre; Sliding Hernia, Gastric volvulus
Online: 27 November 2023 (11:31:49 CET)
Most abdominopelvic structures can find their way to a groin hernia. However, location, and relative fixation are important for migration. Gastric outlet obstruction (GOO) from a stom-ach-containing groin hernia (SCOGH) is exceedingly rare. In the current report, we present a 77-year-old man who presented with GOO from SCOGH to our facility. We performed a review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) of patient presenting with SCOGH since it was first reported in 1802. Ninety-one cases of SCOGH were identified (85 inguinal and 6 femoral) over the last two centuries (1802-2023). GOO from SCOGH occurred in 48% of patients in one review and 18% in our world literature review, but initial presentation ranged from completely asymptomatic to peritonitis. Man-agement varied from entirely conservative treatment to elective hernia repair to emergent lap-arotomy. Only one case of laparoscopic management was documented. Twenty-one deaths from SCOGH were reported, with most occurring in early manuscripts (1802-1896 [n=9] and 1910-1997 [n=10]). In the recent medical era, outcomes for patients with this rare clinical presentation are satisfactory and treatment ranging from conservative, non-operative management to surgical repair should be tailored towards patients’ clinical presentation.
ARTICLE | doi:10.20944/preprints202203.0005.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Helicobacter pylori; gastric cancer; Navajos; Native Americans; American Indians; virulence factors
Online: 1 March 2022 (06:52:14 CET)
Background: In Arizona Helicobacter pylori prevalence of infection among Navajo adults is about 62% and gastric cancer incidence rate is 3-4 times higher than that of the non-Hispanic White population. Aim: The aim of this study was to estimate the prevalence of specific H. pylori virulence factors (cagA and vacA) among Navajo patients undergoing and their association with gastric disease. Methods: Virulence genes, cagA and vacA, in H. pylori were investigated in gastric biopsies from 96 Navajo patients over age 18 who were undergoing esophagogastroduodenoscopy. Biopsies from the antrum and fundus were used for molecular characterization to determine cagA type and number of EPIYA motifs and presence of alleles in the signal (s) and medium (m) regions of the vacA gene. Results: H. pylori infection was found in 22.9% of the biopsy samples. The cagA gene amplified in 57.6% of samples and showed a predominant “Western cagA” type, with the EPIYA-ABC motif (45.4%), most prevalent. The vacA allele s1bm1 was the most prevalent (54.5%). Conclusions: H. pylori genotypes were predominantly cagA Western-type and ABC EPIYA motifs. The vacA s1bm1 genotype was the most prevalent and seemed to be associated with gastritis. American Indian/Alaska Native populations are at higher risk for gastric cancer. It is important to identify genotypes of H. pylori and virulence factors involved in the high prevalence of H. pylori and associated disease among the Navajo population.
REVIEW | doi:10.20944/preprints202001.0025.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: duodenal ulcer; pathogenesis; gastric acid; helicobacter pylori; psychosomatic disease; psychological stress
Online: 3 January 2020 (09:00:37 CET)
Background: The pathogenesis of duodenal ulcer has never been explained although the first description of this disease in medical literature appeared in 1817. Marshall et al. concluded that Helicobacter pylori was the most important etiological factor for duodenal ulcer in 1988, but the etiology based on this bacterium is controversial and how the bacterial infection leads to ulceration is presently unknown. Objectives: This study aims to identify the cause of duodenal ulcer, address the controversial issues surrounding Helicobacter pylori, elucidate the roles of gastric acid, and describe the pathological process of duodenal ulceration. Methods: First, a comprehensive systematic review on peptic ulcers (including gastric ulcer and duodenal ulcer) was conducted and the results were summarized. Second, a recently published causal relationship was employed to identify the etiology of peptic ulcers. Third, novel concepts and methods were applied to analyze the existing data on duodenal ulcer. Results: The etiology of duodenal ulcer and the roles of Helicobacter pylori and gastric acid in this disease were identified. The controversies surrounding Helicobacter pylori were addressed, and many characteristics and phenomena/observations of duodenal ulcer were elucidated. The pathological process of duodenal ulceration was described. Conclusion: Existing data accumulated over the past 300 years was sufficient, when analyzed using novel concepts, to understand the pathogenesis of duodenal ulcer. Duodenal ulcer is not an infectious disease caused by the infection of Helicobacter pylori, but a psychosomatic disease triggered by psychological stress. Helicobacter pylori plays a secondary role in only the late phase of duodenal ulceration.
ARTICLE | doi:10.20944/preprints202305.2269.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: EBV oncogenes; LMP1; Nasopharyngeal; gastric carcinomas; mouse model; tumor suppression and prevention
Online: 31 May 2023 (14:42:00 CEST)
Abstract: The study aimed to investigate the antitumor efficacy of anti-LMP1 antibodies in EBV-positive nasopharyngeal and stomach cell lines and xenograft models. The study also exam-ined the NF-κB expression and cell cycle activation of NPC serum exosome-associated LMP1. An-ti-LMP1 antibody treatment before or during cell implantation prevented tumor growth in nude mice. A small dose of antibodies resulted in complete tumor regression for at least three months af-ter the tumors had grown in size. The consumption of antigen-antibody complexes by tumor cells limited tumor growth. In vitro experiments showed that anti-LMP1 antibodies killed EBV-positive NPC- or GC-derived epithelial cell lines and EBV-positive human B cell lines but not EBV-negative cell lines. Treatment with anti-LMP1 reduced NF-κB expression in cells. The animal model experi-ments showed anti-LMP1 inhibited and prevented NPC- or GC-derived tumor growth. The results suggest that LMP1 antibody immunotherapy could cure nasopharyngeal cancer, EBV-positive gastric carcinoma, and EBV-associated lymphomas. However, further validation of these findings is required through human clinical trials.
REVIEW | doi:10.20944/preprints202311.1632.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: checkpoint inhibitors; esophageal cancer; gastric cancer; immunotherapy; PD-L1; HER2; clinical trials; history; disparities
Online: 28 November 2023 (01:45:08 CET)
Esophagogastric cancers are among the most common and deadly cancers worldwide. This review traces their chronology from 3000 BCE to the present. The first several thousand years were devoted to palliation, before advances in operative technique and technology led to the first curative surgery in 1913. Systemic therapies were introduced in 1910, and radiotherapy shortly thereafter. Operative technique improved massively over the 20th century, with operative mortality rates reducing from over 50% in 1933 to less than 5% by 1981. In addition to important roles in palliation, endoscopy became a key non-surgical curative option for patients with limited-stage disease by the 1990s. The first nonrandomized studies on combination therapies (chemotherapy +/- radiation +/- surgery) were reported in the early 1980s, with survival benefit only for subsets of patients. Randomized trials over the next decades had similar overall results, with increasing nuance. Disparate conclusions led to regional variation in global practice. Starting with the first FDA approval in 2017, multiple immunotherapies now encompass more indications and earlier lines of therapy. As standards of care incorporate these effective yet expensive therapies, care must be given to disparities and methods for increasing access.
BRIEF REPORT | doi:10.20944/preprints202311.1365.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: owel preparation; Duodenal lesions; Gastric lesions; Oral sulfate solution (OSS); polyethylene glycol (PEG)
Online: 22 November 2023 (03:39:59 CET)
Background: During esophagogastroduodenoscopy performed with colonoscopy, gastric and duodenal erythema, erosions, and ulcerations are often observed. This investigation was designed to review the prevalence of gastroduodenal lesions in patients who underwent wireless capsule endoscopy using standard bowel cleansing preparations, but no endoscopy or sedation. Methods: A retrospective analysis was conducted on patients referred for capsule endoscopy. Records and capsule reports were reviewed for patient demographics, preparation prescribed, procedural indications, and gastroduodenal findings. Preparations studied included polyethylene glycol lavage (PEG), PEG plus bisacodyl (PEG+bis), bisacodyl (bis), oral sulfate solution (OSS) and no prep. Results: Among the 1236 records, 498 (40.3%) were men and 738 (59.7%) were women. The mean age was 57 years +/- 17.8 years SD. The percentage of patients with lesions after any bowel preparation was 52.7% for gastric lesions and 23.6% for duodenal lesions. The percentage of patients with gastroduodenal lesions was 58.3% with prep, compared to 38.2% without prep. These findings were statistically significant with RR 1.53 [1.19-1.94] (p-value=0.00004). This difference was more pronounced in the OSS group RR 1.65 [1.29-2.1] and bisacodyl groups RR 1.64 [1.25-2.15] compared to the PEG group RR 0.95 [0.7-1.3]. Conclusion: This study showed that patients undergoing wireless capsule endoscopy who received bowel preparations had a significant increase in gastric and duodenal lesions. Of the preparations studied, OSS was associated with the greater number of gastroduodenal lesions, while PEG was the least associated with lesions with an occurrence similar to the non-prep group. The clinical significance of these lesions remains undetermined.
SHORT NOTE | doi:10.20944/preprints202306.1658.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: qPCR assay; probe-based detection; SYBR green; human KRAS gene; human gastric CloTest samples
Online: 23 June 2023 (10:50:59 CEST)
Quantitative polymerase chain reaction (qPCR) is the gold standard approach for detecting a variety of pathogens either via probe-based or SYBR green detection chemistry. Generally, probe-based detection is more specific than SYBR green chemistry. This report describes work done in using a FAM probe targeting a specific segment of the human KRAS gene for detecting presence and relative abundance of the gene in human gastric CloTest samples. Results indicate ineffective detection of the human KRAS gene in samples that are shown to harbor the gene through a similar qPCR assay using SYBR green detection chemistry. Such observations point to inability of the designed FAM probe to bind to target segment of the human KRAS gene that suggests a region of rapid genomic evolution that require close surveillance in the public health community. Given its rapid genomic evolution, this probe region may be an important region in the human KRAS gene playing critical functional roles in either molecular recognition or other structural functions. Overall, human KRAS gene may be undergoing rapid genomic evolution, and qPCR probes targeting specific segment of the gene may be rendered ineffective in short time clinically, thereby, making SYBR green qPCR assay a more reliable choice.
ARTICLE | doi:10.20944/preprints202305.0766.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: lactic acid bacteria; gastric juice; intestinal juice; fatty acid profile; cell survival; health benefits
Online: 10 May 2023 (14:41:00 CEST)
This study aimed to investigate the ability of lactic acid bacteria to remove cholesterol in simulated gastric and intestinal fluids. The findings showed that the amount of cholesterol removed was dependent on the biomass, viability, and bacterial strain. Additionally, some cholesterol binding was stable and not released during gastrointestinal transit. The presence of cholesterol affected the fatty acid profile of bacterial cells, which could potentially influence their metabolism and functioning. However, adding cholesterol did not significantly impact the survival of lactic acid bacteria during gastrointestinal transit. Moreover, the study did not find significant effects of storage time, passage, or bacterial culture type on the cholesterol content of fermented dairy products. The researchers observed differences in cell survival among lactic acid bacteria strains in simulated gastric and intestinal fluids, depending on the environment. Furthermore, dry matter content, such as high milk protein, was more protective of bacterial cells during gastrointestinal transit than fat content. Future research should aim to better understand the impact of cholesterol on lactic acid bacteria metabolism and identify potential health benefits or risks.
REVIEW | doi:10.20944/preprints202311.1775.v1
Subject: Surgery, Medicine And Pharmacology Keywords: GE junction cancer; Esophagogastric cancer; Gastroesophageal cancer; Esophageal cancer; Gastric cancer; Esophagectomy; Gastrectomy; Proximal gastrectomy
Online: 29 November 2023 (04:58:57 CET)
Gastroesophageal (GE) junction adenocarcinoma is an aggressive malignancy of growing incidence and is associated with public health issues such as obesity and GERD. Management has evolved over the last 2 decades to incorporate a multidisciplinary approach including endoscopic intervention, and neoadjuvant chemotherapy/ chemoradiation and minimally invasive or more limited surgical approaches. Surgical approaches include esophagectomy, total gastrectomy, and more recently proximal gastrectomy. This review analyzes the evidence for and applicability of these varied approaches in management as well areas of continued controversy and investigation.
ARTICLE | doi:10.20944/preprints202306.0633.v1
Subject: Public Health And Healthcare, Primary Health Care Keywords: Roux-en-Y Gastric Bypass; Adiponectin to leptin ratio; Inflammatory profile; Severely obese; Metabolic syndrome
Online: 8 June 2023 (10:47:49 CEST)
Obesity is a troubling public health problem worldwide as it increases risks of respiratory complications, systemic arterial hypertension, type 2 diabetes mellitus, sleep disorders, cardiovascular diseases, and metabolic syndrome (MetS). As a measure to counteract comorbidities associated with severe obesity, bariatric surgery stands out. This study aimed to investigate the adiponectin/leptin ratio in women with severe obesity with and without MetS undergone Roux-en-Y Gastric Bypass (RYGB) and to characterize the biochemical, glucose, and inflammatory parameters of blood in women with severe obesity before and after RYGB. Were enrolled female with severe obesity undergoing RYGP with MetS (n=11) and without (n=39). Anthropometric data and blood samples were obtained before and 6 months after RYGB to analyze total cholesterol, low-density lipoprotein (LDL), high- density lipoprotein (HDL), non-HDL total cholesterol, and glucose; and circulating levels of adiponectin and leptin. Significant reductions in weight, body mass index, and glucose, total cholesterol, LDL, and leptin were observed after surgery, with higher levels of HDL, adiponectin, and adiponectin/leptin ratio observed after surgery compared to preoperative values. This study demonstrated that weight loss induced by RYGB in patients with severe obesity with or without MetS improved biochemical and systemic inflammatory parameters, particularly the adiponectin/leptin ratio.
ARTICLE | doi:10.20944/preprints202212.0523.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Roux-en-Y gastric bypass bariatric surgery; vitamin D; Vitamin D Receptor; FokI (rs2228570); TaqI (rs731236)
Online: 28 December 2022 (01:44:32 CET)
(1) Background: Obesity and its comorbidities can cause burdens and limitations. Bariatric surgery (BS) is indicated as a safe procedure to reduce body mass and improve present comorbidities. Yet, several complications were reported, like vitamin D [25(OH)D] deficiency. We evaluated if 25(OH)D serum levels relate to clinical characteristics, symptoms, or habits in women after their BS and whether the vitamin D receptor (VDR) gene's TaqI and FokI polymorphisms affected 25(OH)D levels and the total body bone mineral density (TBBMD). (2) Methods: This cohort cross-sectional comparative analytical prospective study consisted of 27 women, 61.6 ± 5.0 years, submitted to BS one year prior at a public reference hospital, DF-Brazil. All participants were asked to follow the physical and dietary activity recommendations and received vitamin D3 supplements. Their anthropometric, biochemical, and immunological measurements and blood samples were obtained. (3) Results: 73.3% of participants had low 25(OH)D levels, and their levels correlated positively with TBBMD and negatively with systolic pressure. VDR TaqI did not affect 25(OH)D levels, whereas VDR FokI's allele f presence correlated to a median rise in 25(OH)D levels. Neither polymorphism correlated to TBBMD. (4) Conclusions: 25(OH)D levels were positively correlated with TBBMD, negatively with systolic blood pressure, and were higher in those with the VDR FokI allele f.
REVIEW | doi:10.20944/preprints202307.1709.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Gastroparesis; chronic nausea and vomiting; functional dyspepsia; body surface gastric mapping; disorders of gut brain interaction; motility disorders.
Online: 25 July 2023 (11:15:16 CEST)
Chronic gastroduodenal symptoms are prevalent worldwide, and there is a need for new diagnostic and treatment approaches. Several overlapping processes may contribute to these symptoms, including gastric dysmotility, hypersensitivity, gut-brain axis disorders, gastric outflow resistance, and duodenal inflammation. Gastric Alimetry® (Alimetry, New Zealand) is a non-invasive test for evaluating gastric function that combines body surface gastric mapping (high-resolution electrophysiology) with validated symptom profiling. Together, these complementary data streams enable important new clinical insights into gastric disorders and their symptom correlations, with emerging therapeutic implications. A comprehensive database has been established, currently comprising >2,000 Gastric Alimetry tests, including both controls and patients with various gastroduodenal disorders. From studies employing this database, this pa-per presents a systematic methodology for Gastric Alimetry test interpretation, together with an extensive supporting literature review. Reporting is grouped into four sections: Test Quality, Spectral Analysis, Symptoms, and Conclusions. This review compiles, assesses, and evaluates each of these aspects of test assessment, with discussion of relevant evidence, example cases, limitations, and areas for future work. The resultant interpretation methodology is recommended for use in clinical practice and research to assist clinicians in their use of Gastric Alimetry as a diagnostic aid, and is expected to continue to evolve with further development.
CONCEPT PAPER | doi:10.20944/preprints202309.2157.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: bariatric surgery; sleeve gastrectomy; Roux-en-y gastric bypass; obesity; microbiota; gut-brain axis; beck scale; depression; diet; probiotics
Online: 30 September 2023 (07:27:10 CEST)
Keywords: bariatric surgery, sleeve gastrectomy, Roux-en-y gastric bypass, obesity, microbiota, gut-brain axis, beck scale, depression, diet, probiotics
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Roux-en-Y gastric bypass surgery; Weight loss; Food intake; Oral glucose tolerance; Leptin; Leptin receptors; Zucker Fatty fa/fa rats
Online: 12 February 2021 (13:11:41 CET)
Leptin is the archetypal adipokine that promotes a negative whole-body energy balance largely through its action on brain leptin receptors. As such, the sustained weight loss and food intake suppression induced by Roux-en-Y gastric bypass (RYGB) surgery have been attributed to enhancement of leptin receptor signalling. We formally revisited this idea in Zucker Fatty fa/fa rats, an established genetic model of leptin receptor deficiency, and carefully compared their body weight, food intake and oral glucose tolerance after RYGB with that of sham-operated fa/fa (obese) and sham-operated fa/+ (lean) rats. We found that RYGB rats sustainably lost body weight, which converged with that of lean rats and was 25.5 % lower than that of obese rats by the end of the 4 week study period. Correspondingly, daily food intake of RYGB rats was similar to that of lean rats from the second postoperative week, while it was always at least 33.9 % lower than that of obese rats. Further, oral glucose tolerance of RYGB rats was normalized at the forth postoperative week. These findings assert that leptin is not an essential mediator of the sustained weight loss and food intake suppression as well as the improved glycemic control induced by RYGB, and instead point to additional circulating and/or neural factors.
REVIEW | doi:10.20944/preprints201807.0525.v2
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: 4-Hydroxynonenal; lipid peroxidation; redox balance; oxidative stress; stomach; peptic ulcer; gastritis; Helicobacter pylori; gastric cancer; non-steroid anti-inflammatory drugs-induced gastropathy
Online: 23 August 2018 (04:24:43 CEST)
Maintenance of integrity and function of the gastric mucosa (GM) requires a high regeneration rate of epithelial cells during the whole life span. The health of the gastric epithelium highly depends on redox homeostasis, antioxidant defense and activity of detoxifying systems within the cells as well as robustness of blood supply. Bioactive products of lipid peroxidation, in particular second messengers of free radicals, the bellwether of which is 4-hydroxynonenal (HNE), are important mediators in physiological adaptive reactions and signaling but they are also thought to be implicated in the pathogenesis of numerous gastric diseases. Molecular mechanisms and consequences of increased production of HNE and its protein adducts in response to stressors during acute and chronic gastric injury are well studied. However, several important issues related to the role of HNE in gastric carcinogenesis, tumor growth and progression, the condition of GM after eradication of Helicobacter pylori, or the relevance of antioxidants for HNE-related redox homeostasis in GM still need more studies and new comprehensive approaches. In this regard, preclinical studies and clinical intervention trials are required, which should also include the use of state-of-the-art analytical techniques such as HNE determination by immunohistochemistry and ELISA as well as modern mass-spectroscopy methods.