ARTICLE | doi:10.20944/preprints202306.2242.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: malignant pleural mesothelioma; oxidative stress; redox-sensitive factors; asbestos; epithelial mesenchymal transition; proliferation
Online: 30 June 2023 (14:41:47 CEST)
Malignant Pleural Mesothelioma (MPM) is an aggressive cancer associated to asbestos exposure. MPM pathogenesis has been related both to oxidative stress, evoked by and in response to asbestos fibers exposure, and the Epithelial Mesenchymal Transition (EMT), an event induced by oxidative stress itself and related to cancer proliferation and metastasis. Asbestos related primary oxidative damage is counteracted in the lung by various redox-sensitive factors, often hyperactivated in some cancers. Among these redox-sensitive factors, Apurinic-apyrimidinic endonuclease 1 (APE-1)/Redox effector factor 1 (Ref-1) has been demonstrated to be overexpressed in MPM and lung cancer, but the molecular mechanism has not yet fully understood. Moreover, asbestos exposure has been associated to induced EMT event, via some EMT transcription factors, such as Twist, Zeb-1 and Snail-1, in a possible crosstalk with oxidative stress and inflammation events. To demonstrate this hypothesis, we inhibited/silenced Ref-1 in MPM cells: as a consequence, both EMT (Twist, Zeb-1 and Snail-1) markers and cellular migration/proliferation were significantly inhibited. Take as a whole, these results show, for the first time, a crosstalk between oxidative stress and EMT in MPM carcinogenesis and invasiveness, so improving the knowledge to better address a preventive and therapeutic approach against this aggressive cancer.
REVIEW | doi:10.20944/preprints201709.0162.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: omega-3; PUFA; chemoresistance; membrane; DHA; EPA
Online: 29 September 2017 (18:32:40 CEST)
The efficacy of chemotherapy depends on sensitivity and intrinsic or acquired drug resistance of cancer cells. The n-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs) are considered chemosensitizing agents and revertants of multidrug resistance by pleiotropic mechanisms. The specific mechanisms are not fully understood, but nowadays, it is widely accepted that there are a complex network of mechanisms, including alteration in gene expression, modulation of cellular proliferation and differentiation, induction of apoptosis, generation of reactive oxygen species and lipid peroxidation. A crucial mechanism in the control of cell drug uptake and efflux is related to n-3 LCPUFA influence on membrane lipid composition. The incorporation of docosahexaenoic acid in the lipid rafts produces significant changes in their physical-chemical properties affecting content and functions of transmembrane proteins, such as growth factors, receptors and ATP-binding cassette transporters. Of note, n-3 LCPUFAs often impact on the lipid compositions more in chemoresistant cells than in chemosensitive cells, suggesting their adjuvant role in cancer treatment.
ARTICLE | doi:10.20944/preprints202305.1698.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Cancer; Aggressiveness; Mitochondria; Acadvl; Fatty acid beta oxidation; Biomarker; Proteomics; Malignant mesothelioma
Online: 24 May 2023 (05:06:41 CEST)
Recent reports suggest that dysregulation of lipid metabolism is a key feature of the most invasive cancers. To identify potential biomarkers of tumor aggressiveness, we compared the proteomes of two experimental models of malignant mesothelioma in rats exhibiting different invasive properties. Quantitative changes between the most invasive, M5-T1, versus the least invasive, F4-T2, first led to a list of 424 proteins. A second step, cross-comparing this list with 433 proteins distinguishing invasive vs non-invasive tumors, led to identifying 88 proteins that specifically increased and 157 that decreased, respectively, characterizing the most aggressive M5-T1 tumor. Among the 15 mitochondrial proteins found in these lists, the very long-chain specific acyl-CoA dehydrogenase, encoded by the Acadvl gene and involved in fatty acid beta oxidation, appeared to play an important role in the metabolic reprogramming of the tumor microenvironment. Immunohistochemical staining of tumor sections confirmed increased expression of Acadvl in the M5-T1 tumor. Finally, the dramatic increase and decrease, observed in 25 and 17 proteins, respectively, suggested the existence of a strong link between mitochondrial events and modifications of the extracellular matrix, immune cell components or other subcellular compartments. These findings highlight some important aspects of the tumor microenvironment changes linked to aggressiveness.
ARTICLE | doi:10.20944/preprints201805.0196.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: P-glycoprotein; glioblastoma multiforme; brain-blood barrier; doxorubicin
Online: 14 May 2018 (12:50:18 CEST)
P-glycoprotein (Pgp) determines resistance to a broad spectrum of drugs in glioblastoma multiforme (GB) because it is highly expressed in GB stem cells and in brain-blood barrier (BBB), the peculiar endothelium surrounding brain. Inhibiting Pgp activity in BBB and GB is still an open challenge. Here, we tested the efficacy of a small library of tetrahydroisoquinoline derivatives with an EC50 for Pgp < 50 nM, in primary human BBB cells and in patients-derived GB, from which we isolated differentiated/adherent cells (AC, i.e. Pgp-negative/doxorubicin-sensitive cells) and stem cells (neurospheres, NS, i.e. Pgp-positive/doxorubicin-resistant cells). At 1 nM, 3 compounds increased the delivery of doxorubicin, a typical substrate of Pgp, across BBB monolayer, without altering expression and activity of other transporters. The compounds increased the drug accumulation within NS, restoring necrosis, apoptosis and reduction in cell viability induced by doxorubicin. In co-culture systems, the compounds added to the luminal face of BBB increased the delivery of doxorubicin to NS growing under BBB and rescued the drug’s cytotoxicity. Our work identified new ligands of Pgp active at low nanomolar concentrations, that effectively reduce Pgp activity in BBB and GB, and can improve chemotherapy efficacy in this tumor.
ARTICLE | doi:10.20944/preprints202305.0978.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: malignant mesothelioma; metabolism; mitochondria; long-chain specific acyl-CoA dehydrogenase; fatty acid β-oxidation, biomarker
Online: 15 May 2023 (05:27:55 CEST)
Cross-species investigations on cancer invasiveness are a new approach that identified new biomarkers potentially useful for improving tumor diagnosis and prognosis in clinical medicine and veterinary science. In this study, we combined proteomic analysis of four experimental rat malignant mesothelioma (MM) tumors with analysis of ten patient-derived cell lines to identify common features associated to mitochondrial proteome rewiring. The comparison of significant abundance changes between invasive and non-invasive rat tumors rat tumors gave a list of 433 proteins, including twenty-six proteins reported to be exclusively located in mitochondria. Next, we analyzed the differential expression of genes encoding the mitochondrial proteins of interest in five primary epithelioid and five primary sarcomatoid human MM cell lines, and the most impressive increase was observed in the expression of the long-chain acyl coenzyme A dehydrogenase (ACADL). To evaluate the role of this enzyme in the migration/invasiveness, two epithelioid and two sarcomatoid human MM cell lines derived from patients with the highest and lowest overall survival were studied. Interestingly, sarcomatoid vs epithelioid cell lines were characterized by higher migration and fatty oxidation rates, in agreement with ACADL findings. These results suggest that evaluating mitochondrial proteins in MM specimens might identify tumors with higher invasiveness.