REVIEW | doi:10.20944/preprints201912.0388.v1
Subject: Biology, Other Keywords: cancer stem cells; plasticity; Epithelial-Mesenchymal Transition; metastasis; microenvironment
Online: 29 December 2019 (14:51:39 CET)
Intratumoral heterogeneity is a major ongoing challenge in the effective therapeutic targeting of cancer. Accumulating evidence suggests that a fraction of cells within a tumor termed Cancer Stem Cells (CSCs) are primarily responsible for this diversity resulting in therapeutic resistance and metastasis. Adding to this complexity, recent studies have shown that there can be different subpopulations of CSCs with varying biochemical and biophysical traits resulting in varied dissemination and drug-resistance potential. Moreover, cancer cells can exhibit a high level of plasticity or the ability to dynamically switch between CSC and non-CSC states or among different subsets of CSCs. The molecular mechanisms underlying such plasticity has been under extensive investigation and the trans-differentiation process of Epithelial to Mesenchymal transition (EMT) has been identified as a major contributing factor. Besides genetic and epigenetic factors, CSC plasticity is also shaped by non-cell-autonomous effects such as the tumor microenvironment. In this review, we discuss the recent developments in understanding CSC plasticity in tumor progression at biochemical and biophysical levels, and the latest in silico approaches being taken for characterizing cancer cell plasticity with implications in improving existing therapeutic approaches.
ARTICLE | doi:10.20944/preprints202110.0198.v1
Subject: Medicine & Pharmacology, Pharmacology & 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.
REVIEW | doi:10.20944/preprints202012.0659.v1
Online: 25 December 2020 (13:00:28 CET)
Pirin is an oxidative stress (OS) sensor belonging to the functionally diverse cupin superfamily of proteins. Pirin is a suggested quercetinase and transcriptional activator of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Its biological role in cancer development remains as a novel area of study. This review shows accumulating evidence on the contribution of Pirin in epithelial cancers, signaling pathways involved, and as a suggested therapeutic target. Finally, we propose a model in which Pirin is upregulated by physical, chemical or biological factors involved in OS and cancer development.
REVIEW | doi:10.20944/preprints202007.0713.v1
Subject: Keywords: Mesenchymal Epithelial Transition; Cellular Reprogramming; OVOL1; OVOL2; Epithelial Mesenchymal Transition
Online: 30 July 2020 (10:21:43 CEST)
OVOL proteins (OVOL1 and OVOL2), vertebrate homologs of Drosophila OVO, are critical regulators of epithelial lineage determination and differentiation during embryonic development in tissues such as kidney, skin, mammary epithelia, testis. OVOL inhibits EMT and can promote MET; moreover, they can regulate the stemness of cancer cells, thus playing an important role during cancer cell metastasis. Due to their central role in differentiation and maintenance of epithelial lineage, OVOL overexpression has been shown to be capable of reprogramming fibroblasts to epithelial cells. Here, we review the roles of OVOL mediated epithelial differentiation across multiple contexts – embryonic development, cancer progression, and cellular reprogramming.
ARTICLE | doi:10.20944/preprints202001.0252.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: signal transduction; γ-ionizing radiation; cancer invasion; non-small cell lung cancer; epithelial-mesenchymal transition; tumor microenvironment
Online: 22 January 2020 (03:04:00 CET)
Previously, we demonstrated that IR triggers the invasion/migration of A549 cells via activation of an EGFR–p38/ERK–STAT3/CREB-1–EMT pathway. Here, we have demonstrated the involvement of a novel intracellular signaling mechanism in γ-ionizing radiation (IR)-induced migration/invasion. Expression of receptor-interacting protein (RIP) 1 was initially increased upon exposure of A549, a non-small cell lung cancer (NSCLC) cell line, to IR. IR-induced RIP1 is located downstream of EGFR and involved in the expression/activity of matrix metalloproteases (MMP-2 and MMP-9) and vimentin, suggesting a role in epithelial-mesenchymal transition (EMT). Our experiments showed that IR-induced RIP1 sequentially induces Src-STAT3-EMT to promote invasion/migration. Inhibition of RIP1 kinase activity and expression blocked induction of EMT by IR and suppressed the levels and activities of MMP-2, MMP-9, and vimentin. IR-induced RIP1 activation was additionally associated with stimulation of the transcriptional factor NF-κB. Specifically, exposure to IR triggered NF-κB activation and inhibition of NF-κB suppressed IR-induced RIP1 expression followed by a decrease in invasion/migration as well as EMT. Based on the collective results, we propose that IR concomitantly activates EGFR and NF-κB and subsequently triggers the RIP1–Src/STAT3–EMT pathway, ultimately promoting metastasis.
ARTICLE | doi:10.20944/preprints202101.0490.v1
Subject: Biology, Anatomy & Morphology Keywords: CD44; Cancer Stem Cells; Tumorigenesis; Drug Resistance; Immune Markers; Epithelial to Mesenchymal Transition; Therapeutic Targeting
Online: 25 January 2021 (12:23:49 CET)
One of the most used markers of cancer stem cells in several cancers, including colorectal cancer and breast cancer, is CD44. CD44 is a glycoprotein that traverses the cell membrane and binds to many ligands including hyaluronan resulting in activation of signaling cascades. Several reports have shown conflicting data on the expression of CD44 and that the expression depends on modes of investigations and subtypes of cancers. In addition, the correlation between CD44 expression and drug resistance, immune infiltration, EMT, metastasis and patients prognosis in several cancer types remains unclear. This study investigated CD44 expression in several cancers and explored its relationship with tumorigenesis using various publicly available databases, including The Cancer Genome Atlas, GEPIA, Oncomine, Genomics of Drug Sensitivity in Cancer and Tumor Immune Estimation Resource. Our analysis reveals that CD44 is differentially expressed in different cancers. CD44 expression is significantly associated with cancer patients’ survival in gastric, pancreatic and colorectal cancers. In addition, CD44 expression is closely linked with immune infiltration and immune suppressive features in pancreatic, colon adenocarcinoma and stomach cancer. High CD44 expression was significantly correlated with the expression of drug resistance-, EMT- and metastasis- linked genes. Tumors expressing high CD44 have higher mutation burden and afflict older patients than tumors expressing low CD44. Cell lines expressing high CD44 are more resistant to anti-cancer drugs compared to those expressing low CD44. Protein-protein interaction investigations and functional enrichment analysis showed that CD44 interacts with gene products related to cell-substrate adhesion, migration, platelet activation, and cellular response to stress. KEGG pathway analysis revealed that these genes play key roles in biological adhesion, cell component organization, locomotion, G-α-signaling and the response to stimulus. Overall, this investigation reveals that CD44 play significant roles in tumorigenesis, can be used as a prognostic biomarker in several cancers and can be therapeutically targeted in cancer therapy.
Subject: Biology, Anatomy & Morphology Keywords: epithelial mesenchymal plasticity (EMP); epithelial mesenchymal transition (EMT); mesenchymal epithelial transition (MET); E/M Hybrid; partial EMT; computational biology; mathematical modeling; cancer
Online: 10 February 2021 (15:04:19 CET)
The epithelial-mesenchymal (E/M) hybrid state has emerged as an important mediator of elements of cancer progression, facilitated by epithelial mesenchymal plasticity (EMP). We review here evidence for the presence, prognostic significance, and therapeutic potential of the E/M hybrid state in carcinoma. We further assess modelling predictions and validation studies to demonstrate stabilised E/M hybrid states along the spectrum of EMP, as well as computational approaches for characterising and quantifying EMP phenotypes, with particular attention to the emerging realm of single-cell approaches through RNA sequencing and protein-based techniques.
ARTICLE | doi:10.20944/preprints202105.0354.v1
Online: 14 May 2021 (17:05:25 CEST)
Multi-walled carbon nanotubes are engineered nanomaterials (ENMs) that have a fiber-like structure which may be a concern for the development of cellular senescence. Premature senes-cence, a state of irreversible cell cycle arrest, is implicated in the pathogenesis of chronic lung dis-eases such as pulmonary fibrosis (PF). However, the crosstalk between downstream pathways mediating fibrotic and senescent responses of MWCNTs is not well defined. Here, we exposed human bronchial epithelial cells (BEAS2B) to MWCNTs for up to 72 hours and demonstrate that MWCNTs increase reactive oxygen species production (ROS) accompanied by inhibition of cell growth and proliferation. In addition, exposure resulted in the increase of p21 protein and senes-cence associated β-galactosidase (SA β-gal) activity. We also determined that co-exposure with the cytokine, transforming growth factor-β (TGF-β) exacerbated cellular senescence indicated by increased protein levels of p21, p16, and γH2A.X Furthermore, the production of fibronectin and plasminogen activator inhibitor (PAI-1) was significantly elevated with the co-exposure compared to MWCNTs or TGF-β alone. Together, this suggests that the senescence potential of MWCNTs may be enhanced by pro-fibrotic mediators in the surrounding microenvironment.
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: cancer; epithelial-mesenchymal transition; hybrid; metastasis
Online: 3 February 2020 (06:54:32 CET)
Epithelial-mesenchymal transition (EMT) has been well recognized for its essential role in cancer progression as well as normal tissue development. In cancer cells, activation of EMT permits the cells to acquire migratory and invasive abilities and stem-like properties. However, simple categorization of cancer cells into epithelial and mesenchymal phenotypes misleads the understanding of the complicated metastatic process, and contradictory results from different studies also indicate the limitation of application of EMT theory in cancer metastasis. Nowadays, growing evidence suggests the existence of an intermediate status between epithelial and mesenchymal phenotypes, i.e., the “hybrid epithelial-mesenchymal (hybrid E/M)”state, provides a possible explanation for those conflicting results. Appearance of hybrid E/M phenotype offers a more plastic status for cancer cells to adapt the stressful environment for proceeding metastasis. In this article, we review the biological importance of the dynamic changes between the epithelial and the mesenchymal states. The regulatory mechanisms encompassing the translational, post-translational, and epigenetic control for this complex and plastic status are also discussed .
ARTICLE | doi:10.20944/preprints202010.0114.v1
Online: 6 October 2020 (09:43:40 CEST)
Prevalence studies of current smoking among hospitalized COVID-19 patients demonstrated an unexpectedly low prevalence of current smoking among patients with COVID-19. The aim of the present proposal was to evaluate the effect of smoke from cigarettes on ACE-2 in bronchial epithelial cells. Normal bronchial epithelial cells (H292) were exposed to smoke by an air-liquid-interface (ALI) system and ACE-2 membrane protein expression was evaluated after 24 hours from exposure. Our transcriptomics data analysis showed a significant selective reduction of membrane ACE-2 expression (about 25%) following smoking exposure. Interestingly, we observed a positive direct correlation between ACE-2 reduction and nicotine delivery. Furthermore, by stratifying GSE52237 as a function of ACE-2 gene expression levels, we highlighted 1012 genes related to ACE-2 in smokers and 855 in non-smokers. Furthermore, we showed that 161 genes involved in the endocytosis process were highlighted using the online pathway tool KEGG. Finally, 11 genes were in common between the ACE-2 pathway in smokers and the genes regulated during endocytosis, while 12 genes with non-smokers. Interestingly, six in non-smokers and four genes in smokers were closely involved during the viral internalization process. Our data may offer a pharmaceutical role of nicotine as potential treatment option in COVID-19.
ARTICLE | doi:10.20944/preprints202112.0033.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: IPF; alveolar epithelial cells; intermediate epithelial cells; transitional states, lysotracker; flow cytometry; lung transcriptomic profile, CK5; NGFR; CD24
Online: 2 December 2021 (11:38:12 CET)
Idiopathic lung fibrosis (IPF) is a progressive and fatal degenerative lung disease of unknown etiology. Although in its final stages it implicates in a reactive manner all lung cell types, the initial damage involves the alveolar epithelial compartment, in particular the alveolar epithelial type 2 cells (AEC2s). AEC2s serve dual progenitor and surfactant secreting functions, both of which are deeply impacted in IPF. Thus, we hypothesize that the size of the surfactant processing compartment, as measured by Lysotracker incorporation, allows the identification of different epithelial states in the IPF lung. Flow cytometry analysis of epithelial Lysotracker incorporation delineates two populations (Lysohigh and Lysolow) of AEC2s which behave in a compensatory manner during bleomycin injury and in the donor/IPF lung. Employing flow cytometry and transcriptomic analysis of cells isolated from donor and IPF lungs, we demonstrate that the Lysohigh population expresses all classical AEC2 markers and is drastically diminished in IPF. The Lysolow population, which is increased in proportion in IPF, co-expresses AEC2s and basal cell markers resembling the phenotype of the previously identified intermediate AEC2 population in the IPF lung. In that regard, we provide an in-depth flow-cytometry characterization of Lysotracker uptake, HTII-280, proSP-C, mature SP-B, NGFR, KRT5 and CD24 expression in human lung epithelial cells. Combining functional analysis with extra- and intra- cellular marker expression and transcriptomic analysis, we advance the current understanding of epithelial cell behavior and fate in lung fibrosis.
REVIEW | doi:10.20944/preprints202108.0453.v1
Subject: Keywords: Hybrid epithelial/mesenchymal phenotypes; Collective cell migration; epithelial-mesenchymal heterogeneity; mathematical modeling; cell-state transition; live-cell imaging
Online: 23 August 2021 (14:32:04 CEST)
The Epithelial- Mesenchymal Transition (EMT) is a biological phenomenon associated with explicit phenotypic and molecular changes in cellular traits. Unlike the earlier-held popular belief of it being a binary process, EMT is now thought of as a landscape including diverse hybrid E/M phenotypes manifested by varying degrees of the transition. These hybrid cells can co-express both epithelial and mesenchymal markers and/or functional traits, and can possess the property of collective cell migration, enhanced tumor-initiating ability, and immune/targeted therapy-evasive features, all of which are often associated with worse patient outcomes. These characteristics of the hybrid E/M cells have led to a surge in studies that map their biophysical and biochemical hallmarks that can be helpful in exploiting their therapeutic vulnerabilities. This review discusses recent advances made in investigating hybrid E/M phenotype(s) from diverse biophysical and biochemical aspects by integrating live cell-imaging, cellular morphology quantification and mathematical modeling, and highlights a set of questions that remain unanswered about the dynamics of hybrid E/M states.
ARTICLE | doi:10.20944/preprints202009.0623.v1
Subject: Medicine & Pharmacology, Allergology Keywords: cross-polarization optical coherence tomography (CP OCT); ultrasound; urethral pain syndrome; epithelial atrophy; epithelial hyperplasia; inflammation; fibrosis; image evaluation
Online: 26 September 2020 (11:23:45 CEST)
Urethral pain syndrome (UPS) is still a pathology in which the diagnosis is formulated as a "diagnosis of exclusion". The exact pathogenetic mechanisms are not yet fully understood and clear recommendations for the prevention and treatment of UPS are absent. The goal of the study was to assess the condition of the tissues in the female urethra in UPS, by using transvaginal ultrasound (TVUS) and cross-polarization optical tomography (CP OCT). TVUS showed an expansion in the diameter of the internal lumen of the urethra, especially in the proximal region compared with the norm. Compression elastography revealed areas with increased stiffness (presence of fibrosis) in urethral and surrounding tissues. When studied with CP OCT it was shown that with UPS, the structure of the tissues in most cases was changed: trophic alterations in the epithelium (hypertrophy or atrophy) and fibrosis of underlying connective tissue were observed. The proximal fragment of the urethra with UPS underwent changes identical to those of the bladder neck. This paper showed that the introduction of new technology — CP OCT — in conjunction with TVUS will allow verification of structural changes in tissues of the lower urinary tract at the level of their architectonics and will help doctors understand better the basics of the UPS pathogenesis.
ARTICLE | doi:10.20944/preprints202105.0634.v1
Subject: Medicine & Pharmacology, Allergology Keywords: silica; nanoparticles; ATP; purinergic receptor; airway; epithelial cell
Online: 26 May 2021 (11:45:50 CEST)
Because of their low cost and easy production silica nanoparticles (NPs) are amply used in multiple manufactures as anti-caking, densifying and hydrophobic agents. However, this has increased the exposure levels of the general population and has raised concerns about possible toxicity of this nanomaterial. NPs are known to affect the function of the airway epithelium, but the biochemical pathways targeted by these particles remain largely unknown. Here we investigated the effects of NPs on the responses of cultured human bronchial epithelial (16HBE) cells to the damage-associated molecular pattern ATP, using fluorometric measurements of intracellular Ca2+ concentration. Upon stimulation with extracellular ATP these cells displayed a concentration-dependent increase in intracellular Ca2+, which was mediated by release from intracellular stores. Silica NPs inhibited the Ca2+ responses to ATP within minutes of application and at low micromolar concentrations, which are significantly faster and more potent than those previously reported for the induction of cellular toxicity and pro-inflammatory responses. NPs-induced inhibition appeared to be independent from the increase in intracellular Ca2+ they produce, and via a non-competitive mechanism. These findings suggest that NPs reduce the ability of airway epithelial cells to mount ATP-dependent protective responses such as the increase in mucociliary clearance and cough.
HYPOTHESIS | doi:10.20944/preprints202101.0514.v1
Subject: Life Sciences, Biochemistry Keywords: Senescence; Immortalization; Epithelial to Mesenchymal Transition; Carcinogenesis; Hypothesis
Online: 25 January 2021 (15:31:18 CET)
The origin of cancer remains one of the most important enigmas in modern biology. The prevailing paradigm has failed to grasp a comprehensive view of the disease. Naturally, therapies developed under the current assumptions are inadequate and cancer is practically an incurable disease. Meanwhile, descriptive studies continuously extend the molecular complexity of cancer without an equivalent advancement in its understanding. Furthermore, they tend to accumulate inconsistencies inexplicable under the classical view. This paper presents a compelling theory of the origin of carcinomas. By hypothesis, a series of generic events in epithelial tissues promoted by cellular aging and inflammation enables the reactivation of developmental programs. The origin of carcinomas in vivo is described as the time-ordered cell state transitions undergone by epithelial cells in the hyperplasia due to replicative senescence and inflammation towards a mesenchymal undifferentiated endogenous cell state with cancerous behavior. In support of the theory, the molecular, cellular, and histopathological evidence is critically reviewed. A plausible model for the origin of carcinomas is presented to explain the mechanism underlying carcinogenesis from an evolutive and developmental perspective. The implications of the hypothesis in the current strategies for cancer prevention and treatment are discussed along with rational alternatives and some predictions for possible experimental validation.
Subject: Medicine & Pharmacology, Allergology Keywords: cancer stem cell; epithelial-mesenchymal transition; molecular network
Online: 25 November 2020 (13:47:19 CET)
Epithelial-mesenchymal transition (EMT) plays an important role in the acquisition of cancer stem cell (CSC) feature and drug resistance, which are the main hallmarks of cancer malignancy. Although previous findings have shown that several signaling pathways are activated in cancer progression, the precise mechanism of signaling pathways in EMT and CSCs are not fully understood. In this study, we focused on the intestinal and diffuse-type gastric cancer (GC), and analyzed the gene expression of public RNAseq data to understand the molecular pathway regulation in different subtypes of gastric cancer. Network pathway analysis was performed by Ingenuity Pathway Analysis (IPA). Total 2815 probe set IDs were significantly different between intestinal- and diffuse-type GC data in cBioPortal Cancer Genomics. The 10 genes including male-specific lethal 3 homolog (Drosophila) pseudogene 1 (MSL3P1), CDC28 protein kinase regulatory subunit 1B (CKS1B), DEAD-box helicase 27 (DDX27), golgi to ER traffic protein 4 (GET4), chromosome segregation 1 like (CSE1L), translocase of outer mitochondrial membrane 34 (TOMM34), YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), ribonucleic acid export 1 (RAE1), par-6 family cell polarity regulator beta (PARD6B), and MRG domain binding protein (MRGBP) were found to have difference in gene expression in intestinal- and diffuse-type GC. Total 463 direct relationships with 3 molecules (MYC, NTRK1, UBE2M) were found in the biomarker-filtered network generated by network pathway analysis. The networks and features in intestinal- and diffuse-type GC have been investigated and profiled in bioinformatics. Our results revealed the signaling pathways networks in intestinal- and diffuse-type GC, bringing new light for the elucidation of drug resistance mechanisms in CSCs.
REVIEW | doi:10.20944/preprints202105.0779.v1
Subject: Biology, Anatomy & Morphology Keywords: Lineage Plasticity; Tumor Progression; Metastasis; Therapy Resistance; Epithelial-Mesenchymal Plasticity
Online: 31 May 2021 (13:48:08 CEST)
Lineage plasticity, the switching of cells from one lineage to another has been recognized to be a cardinal property essential for embryonic development, tissue repair and homeostasis. However, such a highly regulated process goes awry when cancer cells exploit this inherent ability to their advantage, resulting in tumorigenesis, relapse, metastasis and therapy resistance. In this review, we summarize our current understanding on the role of lineage plasticity in tumor progression and therapeutic resistance in multiple cancers. Lineage plasticity can be triggered by treatment itself and is reported across various solid as well as liquid tumors. Here we focus on the importance of lineage switching in tumor progression and therapeutic resistance of solid tumors such as the prostate, lung, hepatocellular and colorectal carcinoma and the myeloid and lymphoid lineage switch observed in leukemias. Besides this, we also discuss the role of Epithelial-Mesenchymal Transition (EMT) in facilitating the lineage switch in biphasic cancers such as aggressive carcinosarcomas. We also discuss the mechanisms involved, current therapeutic approaches and challenges that lie ahead in taming the scourge of lineage plasticity in cancer.
REVIEW | doi:10.20944/preprints202103.0444.v1
Subject: Medicine & Pharmacology, Allergology Keywords: SMAD; Sjӧgren’s syndrome; epithelial-mesenchymal transition; fibrosis; TGF-β; inflammation
Online: 17 March 2021 (14:43:37 CET)
There is considerable interest in delineating the molecular mechanisms of action of transforming growth factor-β (TGF-β), considered as central player in a plethora of human conditions, including cancer, fibrosis and autoimmune disease. TGF-β elicits its biological effects through membrane bound serine/threonine kinase receptors which transmit their signals via downstream signalling molecules, SMADs, which regulate the transcription of target genes in collaboration with various co-activators and co-repressors. Until now, therapeutic strategy for primary Sjӧgren’s syndrome (pSS) has been focused on inflammation, but, recently, the involvement of TGF-β/SMADs signalling has been demonstrated in pSS, although TGFβ family members seems to have ambiguous effects on the function of pSS salivary glands. Based on these premises, this review highlights recent advances in unravelling the molecular basis for the multi-faceted functions of TGF-β in pSS that are dictated by orchestrations of SMADs, and describe TGF-β/SMADs value as both disease markers and/or therapeutic target for pSS.
REVIEW | doi:10.20944/preprints202104.0415.v1
Subject: Keywords: epithelial-mesenchymal plasticity; stemness; landscape; phenotypic plasticity; cancer stem cells; metastasis
Online: 15 April 2021 (12:57:56 CEST)
Establishing macrometastases at distant organs is a highly challenging process for cancer cells, with extremely high attrition rates. A very small percentage of disseminated cells have the ability to dynamically adapt to their changing micro-environments through reversibly switching to another phenotype, aiding metastasis. Such plasticity can be exhibited along one or more axes – epithelial-mesenchymal plasticity (EMP) and cancer stem cells (CSCs) being the two most studied, and often tacitly assumed to be synonymous. Here, we review the emerging concepts related to EMP and CSCs across multiple cancers. Both processes are multi-dimensional in nature; for instance, EMP can be defined on morphological, molecular and functional changes, which may or may not be synchronized. Similarly, self-renewal, multi-lineage potential, and anoikis and/or therapy resistance may not all occur simultaneously in CSCs. Thus, arriving at rigorous functional definitions for both EMP and CSCs is crucial. These processes are dynamic, reversible, and semi-independent in nature; cells traverse the inter-connected high-dimensional EMP and CSC landscapes in diverse paths, each of which may exhibit a distinct EMP-CSC coupling. Our proposed model offers a potential unifying framework for elucidating the coupled decision-making along these dimensions and highlights a key set of open questions to be answered.
ARTICLE | doi:10.20944/preprints202111.0364.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Polymeric micelles; cannabidiol (CBD); spray-drying; ocular drug delivery; corneal epithelial cells
Online: 19 November 2021 (14:48:27 CET)
Ocular drug delivery is one of the most challenging administration routes due to the very low drug bioavailability. In this work, we produce and characterize mucoadhesive mixed polymeric micelles (PMs) made of chitosan and poly(vinyl alcohol) backbones graft-hydrophobized with short poly(methyl methacrylate) blocks and use them to encapsulate cannabidiol (CBD), an anti-inflammatory cannabinoid. CBD-loaded mixed PMs are physically stabilized by ionotropic crosslinking of the CS domains with sodium tripolyphoshate and spray-drying. These mixed PMs display CBD loading capacity of 20% w/w and sizes of 100-200 nm, and spherical morphology (cryogenic-transmission electron microscopy). The good compatibility of the unloaded and CBD-loaded PMs is assessed in a human corneal epithelial cell line. Then, we confirm the permeability of CBD-free PMs and nanoencapsulated CBD in cornea cell monolayers under liquid-liquid and air-liquid conditions. Overall, our results highlight the potential of these polymeric nanocarriers for ocular drug delivery.
BRIEF REPORT | doi:10.20944/preprints202008.0315.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Indoor; PM10; pulmonary disease; inflammation; IFN; type I interferon; cytokine; epithelial cell
Online: 14 August 2020 (09:22:59 CEST)
Indoor dusts are collectively formed from anthropogenic and atmospheric activities. Particle matter 10 (PM10) is inhalable and causes significant inflammation by interaction with the pulmonary epithelial barrier. The mediators involved in bronchial epithelial cells response to dust are remined unknown. The air-liquid interface of our lung on chip model was exposed to indoor dust collected from highly polluted houses in Delhi, India. The media were collected after 4 days and cytokine levels were measured. We found that the concentration of IFN, IFNγ, Interleukin-6 (IL-6), IL1b, TNFa, and Granulocyte monocyte colony stimulating factor (GM-CSF) were significantly increased after exposure to indoor dust. IFN type I pathways were a major response from dust exposure. Further investigation is needed to determine the mechanism of action and targets of dust in bronchial epithelial cells.
ARTICLE | doi:10.20944/preprints201712.0199.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: IBD; intestinal barrier; Lactobacillus reuteri; Lactobacillus acidophilus; Trans Epithelial Electrical Resistance (TEER)
Online: 29 December 2017 (08:36:36 CET)
Maintenance of intestinal barrier integrity is crucial for preventing inflammatory bowel diseases (IBDs) onset and exacerbations. In this work we study the effect of a fixed combination of Lactobacillus reuteri and Lactobacillus acidophilus and herbal extracts in an in vitro inflammation experimental model. Caco-2 cell monolayer was exposed to INF-γ+TNF-α or to LPS; Trans Epithelial Electrical Resistance (TEER) and paracellular permeability were investigated. ZO-1 and occludin tight junctions (TJs) were also investigated by mean of immunofluorescence. The pre-treatment with the fixed combination of probiotics and herbal extracts prevented the inflammation-induced TEER decrease, paracellular permeability increase and TJs translocation. In summary the fixed combination of probiotics and herbal extracts investigated in this research was found to be an interesting candidate for targeting the re-establishment of intestinal barrier function in IBDs conditions.
ARTICLE | doi:10.20944/preprints202209.0090.v1
Subject: Mathematics & Computer Science, Computational Mathematics Keywords: epithelial cell; antibody response; basic reproduction number; transcritical bifurcation; impulsive control; drug holidays
Online: 6 September 2022 (10:25:07 CEST)
Mathematical modeling is crucial in investigating the pandemic of the ongoing coronavirus disease (COVID-19). The primary target area of the SARS-CoV-2 virus is epithelial cells in the human lower repertory track. During this viral infection, infected cells can initiate innate and adaptive immune responses to viral infection. Immune response in COVID -19 infection can lead to longer recovery time and more severe secondary complications. We formulate a target cell limited mathematical model by incorporating a saturation term for SARS-CoV-2 infected epithelial cell loss reliant on infected cell levels. Forward and backward bifurcation between disease-free and endemic equilibrium points has been analyzed. Global stability of both disease-free and endemic equilibrium is provided. We have seen that the disease-free equilibrium is globally stable for $R_0<1$, and endemic equilibrium exists and is globally stable for $R_0>1$. Impulsive application of drug dosing has been applied for the treatment of covid-19 patients. Also, the dynamics of the impulsive system are discussed when a patient takes drug holidays. The numerical simulations are performed in support of our analytical findings and for the qualitative analysis of the system's dynamics with and without impulse drug dosing.
REVIEW | doi:10.20944/preprints202104.0287.v1
Subject: Life Sciences, Biochemistry Keywords: prostate cancer; castrate resistance, non-metastatic CRPC, clinical trial, epithelial mesenchymal transition, STAT3
Online: 12 April 2021 (12:28:10 CEST)
Nearly one third of men will incur biochemical recurrence after treatment for localized prostate cancer. Androgen deprivation therapy (ADT) is the therapeutic mainstay, however almost all patients will eventually transition to a castrate resistant state (castrate resistant prostate cancer, CRPC). Subjects with CRPC generally develop symptomatic metastatic disease (mCRPC) and incur mortality several years later. Prior to metastatic disease, men acquire non-metastatic CRPC (nmCRPC) which lends the unique opportunity for intervention to delay disease progression and symptoms. This review addresses current therapies for nmCRPC, as well as novel therapeutics and pathway strategies targeting men with nmCRPC.
REVIEW | doi:10.20944/preprints202005.0315.v1
Subject: Life Sciences, Biochemistry Keywords: cancer stem cells; tumor microenvironment; metastasis; chemoresistance; epithelial to mesenchymal transition; clinical trials
Online: 19 May 2020 (14:01:27 CEST)
Despite great strides being achieved in improving cancer patients’ outcomes through better therapies and combinatorial treatment, several hurdles still remain due to therapy resistance, cancer recurrence and metastasis. Drug resistance, culminating in relapse and metastatic disease continue to be associated with fatal disease. Cancer stem cells (CSCs) are a subpopulation of cancer cells known to be resistant to therapy and cause metastasis. Whilst the debate on whether CSCs are the origins of the primary tumor rages on, CSCs have been further characterised in many cancers with data illustrating that CSCs display great abilities to self-renew, withstand therapies due to enhanced epithelial to mesenchymal (EMT) properties, enhanced expression of ABC membrane transporters, activation of several survival signaling pathways and increased immune evasion DNA repair mechanisms. CSCs also display great heterogeneity with the consequential lack of specific CSC markers presenting a great challenge to their targeting. In this updated review we re-visit CSCs within the tumor microenvironment (TME) and present novel treatment strategies targeting CSCs. These promising strategies include targeting CSCs-specific properties using small molecule inhibitors, immunotherapy, microRNA mediated inhibitors, epigenetic methods as well as targeting CSC niche-microenvironmental factors and differentiation. Lastly, we present recent clinical trials undertaken to try to turn the tide against cancer by targeting CSC-associated drug resistance and metastasis.
ARTICLE | doi:10.20944/preprints202010.0185.v1
Subject: Biology, Anatomy & Morphology Keywords: Trueperella pyogenes; bovine endometrial epithelial cells; inflammasome; tight junction; apoptosis; Lactobacillus rhamnosus GR-1
Online: 8 October 2020 (22:07:15 CEST)
Trueperella pyogenes is a common opportunistic pathogen which is one of the main causes of postpartum endometritis in dairy cows. As a substitute for antibiotics, the probiotic Lactobacillus rhamnosus GR-1 has been used in a wide range of clinical treatments. Our experiments were designed to establish a model of anti-damage which LGR-1 was used to protect bovine endometrial epithelial cells (BEECs) from inflammatory damage and cell destruction caused by T. pyogenes. Increased expression of NLRP3 inflammasomes and cytokines was observed following T. pyogenes challenge, but this increase was relieved by LGR-1 pretreatment. Immunofluorescence and Western blot analyses revealed that T. pyogenes infection also results in the damage of tight junction proteins in BEECs. The expression levels of Claudin-1, Occludin, and ZO-1 were decreased in cells only infected with T. pyogenes but not in cells pretreated with LGR-1. Moreover, the detection of the anti-apoptotic protein Bcl-2 and apoptotic proteins BAX, cytochrome c, as well as the activating effector caspase-3 revealed that T. pyogenes induced apoptosis of BEECs, which was also confirmed by DAPI staining to observe the morphological changes of the nuclei of cell apoptosis and by TUNEL staining to locate the cells undergoing apoptosis. Our data indicate that LGR-1 ameliorates the T. pyogenes–induced barrier dysfunction of BEECs and pre-application of LGR-1 could be an effective strategy for controlling T. pyogenes infection.
REVIEW | doi:10.20944/preprints202109.0432.v1
Subject: Keywords: Non-genetic heterogeneity; multistability; drug-tolerant persisters; phenotypic plasticity; biological noise; epithelial-mesenchymal plasticity; PAGE4
Online: 24 September 2021 (12:44:34 CEST)
Despite identical genetic constitution, a cancer cell population can exhibit phenotypic variations termed as non-genetic/non-mutational heterogeneity. Such heterogeneity – a ubiquitous nature of biological systems – has been implicated in metastasis, therapy resistance and tumour relapse. Here, we review the evidence for existence, sources and implications of non-genetic heterogeneity in multiple cancer types. Stochasticity/ noise in transcription, protein conformation and/or external microenvironment can underlie such heterogeneity. Moreover, the existence of multiple possible cell states (phenotypes) as a consequence of the emergent dynamics of gene regulatory networks may enable reversible cell-state transitions (phenotypic plasticity) that can facilitate adaptive drug resistance and higher metastatic fitness. Finally, we highlight how computational and mathematical models can drive a better understanding of non-genetic heterogeneity and how a systems-level approach integrating mathematical modelling and in vitro/in vivo experiments can map the diverse phenotypic repertoire, and identify therapeutic vulnerabilities of an otherwise clonal cell population.
Subject: Medicine & Pharmacology, Allergology Keywords: microRNA; epithelial-mesenchymal transition; 5-fluorouracil; oxaliplati; FOLFOX; chemoresistance; pharmacogenetics; pharmacoepigenetics; EMT-transcription factors; biomarker.
Online: 13 November 2020 (10:47:43 CET)
The FOLFOX scheme, based on the association of 5-fluorouracil and oxaliplatin, is the most frequently indicated chemotherapy scheme for patients diagnosed with metastatic colorectal cancer. Nevertheless, development of chemoresistance is one of the major challenges associated with this disease. It has been reported that epithelial-mesenchymal transition (EMT) is implicated in microRNA-driven modulation of tumor cells response to 5-fluorouracil and oxaliplatin. Besides, from pharmacogenomic research it is known that overexpression of genes encoding dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), methylenetetrahydrofolate reductase (MTHFR), the DNA repair enzymes ERCC1, ERCC2, and XRCC1, and the phase 2 enzyme GSTP1 impair the response to FOLFOX. It has been observed that EMT is associated with overexpression of DPYD, TYMS, ERCC1, and GSTP1. In this review we investigated the role of miRNAs as EMT promotors in tumor cells, and its potential effect on upregulation of DPYD, TYMS, MTHFR, ERCC1, ERCC2, XRCC1 and GSTP1 expression, which would lead to resistance of CRC tumor cells to 5-fluorouracil and oxaliplatin. This constitutes a potential mechanism of epigenetic regulation involved in late-onset of acquired resistance in mCRC patients under FOLFOX chemotherapy. Expression of these biomarkers microRNA could serve as tools for personalized medicine, and as potential therapeutic targets in the future.
REVIEW | doi:10.20944/preprints202207.0464.v1
Subject: Medicine & Pharmacology, Urology Keywords: prostate cancer; six-transmembrane epithelial antigen of the prostate; biomarker; immunotherapy; cancer vaccine; T-cell engaging antibody
Online: 29 July 2022 (14:02:03 CEST)
Six-Transmembrane Epithelial Antigen of the Prostate 1-4 (STEAP1-4) compose a family of metalloproteinases involved in iron and copper homeostasis and other cellular processes. Thus far, five homologs are known: STEAP1, STEAP1B, STEAP2, STEAP3, and STEAP4. In prostate cancer, STEAP1, STEAP2, and STEAP4 are overexpressed while STEAP3 expression is downregulated. Although the metalloreductase activities of STEAP1-4 are well-documented, their other biological functions are not. Furthermore, the properties and expression levels of STEAP heterotrimers, homotrimers, heterodimers, and homodimers are not well-understood. Nevertheless, studies over the last few decades have provided sufficient impetus to investigate STEAP1-4 as potential biomarkers and therapeutic targets for prostate cancer. In particular, STEAP1 is the target of many emerging immunotherapies. Herein, we give an overview of the structure, physiology, and pathophysiology of STEAP1-4 to provide context for past and current efforts to translate STEAP1-4 into the clinic.
ARTICLE | doi:10.20944/preprints201910.0358.v1
Subject: Life Sciences, Other Keywords: epithelial-to-mesenchymal transition; TGF-β1; cAMP; A-kinase anchoring protein; Ezrin; AKAP95; Yotiao; cigarette smoke; COPD
Online: 31 October 2019 (02:15:56 CET)
Epithelial-to-mesenchymal transition (EMT) plays a role in chronic obstructive pulmonary diseases (COPD). Cyclic adenosine monophosphate (cAMP) can inhibit transforming growth factor-β1 (TGF-β1) mediated EMT. Although compartmentalization via A-kinase anchoring proteins (AKAPs) is central to cAMP signaling, functional studies on their therapeutic value in the lung EMT process are lacking. Bronchial epithelial (BEAS-2B, primary HAE cells) were exposed to TGF-β1. Epithelial (E-cadherin, ZO-1) and mesenchymal markers collagen Ӏ (mRNA, protein) were analyzed. St-Ht31 disrupted AKAP-PKA interactions. TGF-β1 release was measured by ELISA. TGF-β1-sensitive AKAPs Ezrin, AKAP95 and Yotiao were silenced using siRNA. Cell migration was analyzed by wound healing assay, xCELLigence, Incucyte. Prior to TGF-β1, dibutyryl-cAMP (dbcAMP), fenoterol, rolipram, cilostamide, forskolin were used to elevate intracellular cAMP. TGF-β1 induced morphological changes, decreased E-cadherin but increased collagen Ӏ and cell migration, a process reversed by PF-670462. TGF-β1 altered (mRNA, protein) expression of Ezrin, AKAP95 and Yotiao. St-Ht31 decreased E-cadherin (mRNA, protein), but counteracted TGF-β1-induced collagen Ӏ upregulation. Cigarette smoke (CS) increased TGF-β1 release, activated TGF signaling, augmented cell migration and reduced E-cadherin expression, a process blocked by TGF-β1 neutralizing antibody. Silencing of Ezrin, AKAP95 and Yotiao diminished TGF-β1-induced collagen Ӏ expression, as well as TGF-β1-induced cell migration. Fenoterol, rolipram, and cilostamide, in AKAP silenced cells pointed to distinct cAMP compartments. We conclude that Ezrin, AKAP95 and Yotiao promote TGF-β1-mediated EMT, linked to a TGF-β1 release by CS. AKAP members define the ability of fenoterol, rolipram and cilostamide to modulate the EMT process, and are potential relevant targets in the treatment of COPD.
REVIEW | doi:10.20944/preprints202008.0087.v1
Subject: Biology, Other Keywords: Chronic rhinosinusitis (CR); inflammation; nasal polyps; epithelial to mesenchymal transition (EMT); Polyp derived mesenchymal stem cells (PO-MSCs)
Online: 4 August 2020 (11:07:19 CEST)
Chronic rhinosinusitis is a common inflammatory disease of paranasal sinuses, which causes rhinorrhea, nasal congestion and hyposmia. The genetic predisposition or the exposure to irritants can sustain the inflammatory response and the development of nasal polyposis. Nasal polyps are benign and teardrop-shaped growths that project in the nasal cavities and originate from the ethmoid sinuses. This inflammatory process is associated with high expression of IL-5 cytokine and infiltration of eosinophils. Humanized monoclonal antibodies targeting IL-5 or its receptor, represent a therapeutic strategy in the treatment of nasal polyposis in combination with corticosteroids. The molecular pathogenesis of nasal polyps in CRS patients is associated to the epithelial-mesenchymal transition (EMT), a process in which epithelial cells lose their typical phenotype acquiring a mesenchymal phenotype. TGFβ/SMAD, ERK, and Wnt/β-catenin pathways are altered in EMT during the nasal tissue remodeling. miRNA and inhibitor molecules targeting these altered signaling pathways are able to interfere with EMT; which could lead to alternative therapies. Nasal polyps are an alternative source of mesenchymal stem cells which can be easily isolated from surgical biopsies. A molecular understanding of the biology of PO-MSCs will contribute to delineating inflammatory process underlying the development of nasal polyps.
REVIEW | doi:10.20944/preprints201904.0206.v1
Subject: Life Sciences, Biophysics Keywords: helial-mesenchymal transition; EMT spectrum; hybrid epithelial/mesenchymal phenotypes; CTC clusters; stemness; immune suppression; EMT metrics; systems biology
Online: 18 April 2019 (08:02:27 CEST)
Cancer cells can acquire a spectrum of stable hybrid epithelial/mesenchymal (E/M) states during epithelial-mesenchymal transition (EMT). Cells in these hybrid E/M phenotypes often combine epithelial and mesenchymal features and tend to migrate collectively commonly as small clusters. Such collectively migrating cancer cells play a pivotal role in seeding metastases and their presence in cancer patients indicates an adverse prognostic factor. Moreover, cancer cells in hybrid E/M phenotypes tend to be more associated with stemness which endows them with tumor-initiation ability and therapy resistance. Most recently, cells undergoing EMT have been shown to promote immune suppression for better survival. A systematic understanding of the emergence of hybrid E/M phenotypes and the connection of EMT with stemness and immune suppression would contribute to more effective therapeutic strategies. In this review, we first discuss recent efforts combining theoretical and experimental approaches to elucidate mechanisms underlying EMT multi-stability (i.e. the existence of multiple stable phenotypes during EMT) and the properties of hybrid E/M phenotypes. Following we discuss non-cell-autonomous regulation of EMT by cell cooperation and extracellular matrix. Afterwards, we discuss various metrics that can be used to quantify EMT spectrum. We further describe possible mechanisms underlying the formation of clusters of circulating tumor cells. Last but not least, we summarize recent systems biology analysis of the role of EMT in the acquisition of stemness and immune suppression.
ARTICLE | doi:10.20944/preprints202204.0077.v1
Subject: Life Sciences, Biochemistry Keywords: Delta-9-tetrahydrocannabinol; cannabidiol; cannabinoids; NLRP3 inflammasome; STAT3; TYK2; cytokine storm; interleukins; TNF-α; macrophages; primary lung bronchial epithelial cells
Online: 8 April 2022 (08:51:26 CEST)
Cannabinoids, mainly cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), are the most studied group of compounds obtained from Cannabis sativa because of their several pharmaceutical properties. Current evidence suggests a crucial role of cannabinoids as potent anti-inflammatory agents for the treatment of chronic inflammatory diseases; however, the mechanisms remain largely unclear. Cytokine storm, a dysregulated severe inflammatory response by our immune system, is involved in the pathogenesis of numerous chronic inflammatory disorders, including coronavirus disease 2019 (COVID-19), which results in the accumulation of pro-inflammatory cytokines. Therefore, we hypothesized that CBD and THC reduce the levels of pro-inflammatory cytokines by inhibiting key inflammatory signalling pathways. The nucleotide-binding and oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signalling has been implicated in a variety of chronic inflammatory diseases, which results in the release of pyroptotic cytokines, interleukin-1β (IL-1β) and IL-18. Likewise, the activation of the signal transducer and activator of transcription-3 (STAT3) causes increased expression of pro-inflammatory cytokines. We studied the effects of CBD and THC on lipopolysaccharide (LPS)-induced inflammatory response in human THP-1 macrophages and primary human bronchial epithelial cells (HBECs). Our results revealed that CBD and, for the first time, THC, significantly inhibited NLRP3 inflammasome activation following LPS + ATP stimulation, leading to a reduction in the levels of IL-1β in THP-1 macrophages and HBECs. CBD attenuated the phosphorylation of nuclear factor-κB (NF-κB) and both cannabinoids inhibited the generation of oxidative stress post-LPS. Our multiplex ELISA data revealed that CBD and THC significantly diminished the levels of IL-6, IL-8, and tumor necrosis factor-α (TNF-α) after LPS treatment in THP-1 macrophages and HBECs. In addition, the phosphorylation of STAT3 was significantly downregulated by CBD and THC in THP-1 macrophages and HBECs, which was in turn, attributed to the reduced phosphorylation of tyrosine kinase-2 (TYK2) by CBD and THC after LPS stimulation in these cells. Overall, CBD and THC were found to be effective in alleviating the LPS-induced cytokine storm in human macrophages and primary HBECs, at least via modulation of NLRP3 inflammasome and STAT3 signalling pathways. The encouraging results from this study warrant further investigation of these cannabinoids in vivo.
ARTICLE | doi:10.20944/preprints202005.0296.v2
Subject: Life Sciences, Biophysics Keywords: W-band (75-105 GHz) MMW; H1299 human lung cancer cells; non-tumorigenic MCF-10A human epithelial cells; in vitro
Online: 15 June 2020 (06:44:57 CEST)
Therapeutically effective treatments of cancer are limited. To calibrate the efficiency of the novel technique we recently discovered to modulate cancer cell viability using tuned electromagnetic fields; H1299 human lung cancer cells were irradiated in a sweeping regime of W-band (75-105 GHz) millimeter waves (MMW) at 0.2 mW/cm2 (2 W/m2). Effects on cell morphology, cell death and senescence were examined and compared to that of non-tumorigenic MCF-10A human epithelial cells. MMW irradiation led to alterations of cell and nucleus morphology of H1299 cells, significantly increasing mortality and senescence over 14 days of observation. Extended irradiation of 10 minutes duration resulted in complete death of exposed H1299 cell population within two days, while healthy MCF-10A cells remained unaffected even after 16 minutes of irradiation under the same conditions. Irradiation effects were observed to be specific to MMW treated H1299 cells and absent in the control group of non-irradiated cells. MMW irradiation affected nuclear morphology of H1299 cells only and not of the immortalized MCF-10A cells. Irradiation with low intensity MMW shows an antitumor effect on H1299 lung cancer cells. This method provides a novel treatment modality enabling targeted specificity for various types of cancers.
REVIEW | doi:10.20944/preprints202208.0203.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: neural induction; embryogenesis; tumorigenesis; conjoined twin; Spemann organizer; node; neural default model; neural stemness; tumorigenicity; pluripotency; epithelial-mesenchymal transition; tumor microenvironment
Online: 10 August 2022 (12:10:36 CEST)
Some concepts/hypotheses have been proposed to explain the general rules behind the complexity of tumorigenesis. Characterization of the property of cancer cells and neural stem cells indicates that neural stemness underlies tumorigenicity and pluripotency, leading to the proposal that tumorigenesis represents a process of progressive loss of original cell identity and gain of neural stemness. This reminds of a most fundamental process required for the development of the nervous system and body axis during embryogenesis, i.e., embryonic neural induction. The principle of neural induction is that, in response to extracellular signals that are secreted by the Spemann-Mangold organizer in amphibians or the node in mammals and inhibit epidermal fate in ectoderm, the ectodermal cells assume the neural default fate and turn into neuroectodermal cells. These cells further differentiate into the nervous system and also some non-neural cells via interaction with adjacent tissues. Failure in neural induction leads to failure of embryogenesis, and ectopic neural induction due to ectopic organizer or node activity or activation of embryonic neural genes causes a formation of secondary body axis or conjoined twins. A similar principle underlies tumorigenesis. Increasing evidence has demonstrated that the core property of cancer cells is neural stemness. Therefore, cancer cells are cells with the loss of original cell identity and gain of neural stemness, and consequently tumorigenicity and pluripotency, due to various intra-/extracellular insults in postnatal animals. Unlike that pluripotent cells (embryonic pluripotent cells, neural stem cells and cancer cells) can differentiate and integrate into embryonic development, cancer cells are capable of self-renewal and differentiation, but cannot integrate into normal tissues in a 2 postnatal animal, ultimately leading to tumor formation. Neural induction and the unique property of neural stemness provide an inclusive explanation for embryogenesis, conjoined twin formation and tumorigenesis. Based on these findings, I discuss about some confusion in cancer research, e.g., epithelial-mesenchymal transition, and propose to distinguish the causality and associations, and the causal and supporting factors involved in tumorigenesis, and suggest revisiting the focus of cancer research. Integration of evidence from developmental and cancer biology indicates that neural stemness determines tumorigenicity and pluripotency, and neural induction drives embryogenesis in gastrulating embryos but a similar process drives tumorigenesis in a postnatal animal.
ARTICLE | doi:10.20944/preprints202012.0552.v1
Subject: Life Sciences, Biochemistry Keywords: Nanoparticles; metallic compounds; airborne particulate; occupational environment; in vitro exposure; alternative testing strategies; EpiAirway™; 3D tissue models; respiratory epithelial tissues
Online: 22 December 2020 (10:40:26 CET)
Inhalation is the main route of exposure to airborne pollutants. To evaluate the safety and assess the risks of occupational hazards different testing approaches are used. 3D airway epithelial tissues allow to mimic exposure conditions in vitro, generates human-relevant toxicology data, allows to elucidate mode of action of pollutants. Gilian 3500 pumps equipped with Standard Midget Impingers were used to collect the airborne particulate from woodworking and metalworking environments. EpiAirway™ tissues were used to model half working day (4 h), full working day (8 h), and 3 working day exposures to occupational pollutants. Tissue viability was assessed using MTT assay. RT-qPCR analyses performed to analyze the expression of gelsolin, caspase-3, and IL-6. Tissue morphology was assessed by hematoxylin/eosin staining. Acute exposure to workspace pollutants slightly affected tissue viability and did not change the morphology. Both types of particles suppressed expression of gelsolin, with metalworking samples showing the most pronounced effect. A slight reduction in caspase-3 expression was observed. Particles from metalworking suppressed IL-6 expression. 3D Epithelial tissues can be used to model exposures to airborne pollutants. Exposure to particles from woodworking and metalworking had a minor effect on tissue viability but affected the expression of inflammation and apoptosis-related genes.
ARTICLE | doi:10.20944/preprints202105.0522.v1
Subject: Life Sciences, Biochemistry Keywords: Cerium oxide NPs; acute and subchronic toxicity; in vitro; pulmonary and interstitial cell lines; human airway epithelial model; air-liquid interface; aerosolized NPs.
Online: 21 May 2021 (13:17:36 CEST)
Engineered nanomaterials (ENMs) are of significant relevance due to their unique properties, which have been exploited for widespread applications. Cerium oxide nanoparticles (CeO2-NPs) are one of most exploited ENM in the industry due to their excellent catalytic and multi-enzyme mimetic properties. Thus, toxicological effects of these ENMs should be further studied. Acute and subchronic toxicity of CeO2-NPs were assessed. First an in vitro multi-dose short-term (24h) toxicological assessment was performed in three different cell lines: A549 and Calu3, representing the lung tissue, and 3T3 as an interstitial tissue model. After that, a sub-chronic toxicity assessment (90 days) of these NPs was carried out on a realistic and well stablished reconstituted primary human airway epithelial model (MucilAir™), cultured at the Air-Liquid Interface (ALI), to study long-term effects of these particles. Results showed minor toxicity of CeO2-NPs in acute exposures. However, in subchronic exposures, cytotoxic and inflammatory responses were observed in the human airway epithelial model after 60 days of exposure to CeO2-NPs. These results suggest that acute toxicity approaches may underestimate the toxicological effect of some ENM, highlighting the need of subchronic toxicological studies in order to accurately assess the toxicity of ENM and their cumulative effects in the organism.
REVIEW | doi:10.20944/preprints201912.0386.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: resistance-associated secretory phenotype (RASP); extracellular vesicle (EV); exosome; oncosome; drug resistance; epithelial-mesenchymal transition (EMT); heat shock protein (HSP); cell stress response; hypoxia; acidosis; tumor immunology
Online: 29 December 2019 (13:46:21 CET)
Extracellular vesicles (EVs), such as exosomes or oncosomes are released with molecules unfavorable for survival from cells. In addition, accumulating evidence has shown that tumor cells often eject anti-cancer drugs such as chemotherapeutics and targeted drugs within EVs, a novel mechanism of drug resistance. The EV-releasing, drug resistance phenotype is often coupled with cellular dedifferentiation and transformation, cells undergoing epithelial-mesenchymal transition (EMT) and taking on a cancer stem cell phenotype. Recent studies have shown that the release of EVs is also involved in immunosuppression. The concept of the resistance-associated secretory phenotype (RASP) is reviewed herein.
ARTICLE | doi:10.20944/preprints201807.0317.v3
Subject: Life Sciences, Molecular Biology Keywords: Boswellia serrata Roxb.; Curcuma longa L.; intestinal bowel diseases (IBD); Caco-2; PBMC; HMC-1.1; mast cells; cytokines; trans epithelial electrical resistance (TEER); reactive oxygen species (ROS)
Online: 8 November 2018 (04:53:46 CET)
Inflammatory bowel diseases, which consist of chronic inflammatory conditions of the colon and the small intestine, are considered a global disease of our modern society. Recently, the interest toward the use of herbal therapies for the management of inflammatory bowel diseases has increased because of their effectiveness and favorable safety profile, compared to conventional drugs. Boswellia serrata Roxb. and Curcuma longa L. are amongst the most promising herbal drugs, however, their clinical use in inflammatory bowel diseases is limited and little is known on their mechanism of action. The aim of this work was to investigate the effects of two phytochemically characterized extracts of B. serrata and C. longa in an in vitro model of intestinal inflammation. Their impact on cytokine release and reactive oxygen species production, as well as the maintenance of the intestinal barrier function and on intestinal mucosa immune cells infiltration, has been evaluated. The extracts showed a good protective effect on the intestinal epithelium at 1 µg/ml, with TEER values increasing by approximately 1.5 fold, compared to LPS-stimulated cells. C. longa showed an anti-inflammatory mechanism of action, reducing IL-8, TNF-α and IL-6 production by approximately 30%, 25% and 40%, respectively, compared to the inflammatory stimuli. B. serrata action was linked to its antioxidant effect, with ROS production being reduced by 25%, compared to H2O2-stimulated Caco-2 cells. C. longa and B. serrata resulted to be promising agents for the management of inflammatory bowel diseases by modulating in vitro parameters which have been identified in the clinical conditions.