Project description:Increasing evidence has shown that chemoresistance is related to the process of epithelial-mesenchymal transition (EMT) and increased invasiveness by tongue squamous cell carcinoma (TSCC) cells. Long noncoding RNAs (lncRNAs) play pivotal roles in tumour metastasis and progression. However, the roles and mechanisms of lncRNAs in cisplatin resistance induced EMT and metastasis are not well understood. In this study, a Chemotherapy Induced Long non-coding RNA 1 (CILA1) was discovered by using microarrays and was functionally identified as a regulator of chemo-sensitivity in TSCC cells.Upregulation of CILA1 promotes EMT, invasiveness and chemoresistance in TSCC cells, whereas the inhibition of CILA1 expression induces MET and chemosensitivity and inhibis the invasiveness of cisplatin-resistant cells both in vitro and in vivo. We also found that CILA1 exerts its functions via the activation of the Wnt/ β-catenin signalling pathway.High CILA1 expression levels and low levesl of phosphorylated β-catenin were closely associated with cisplatin-resistance and advanced disease stage, and were predictors of poor prognosis in TSCC patients. These findings provided a new biomarker for Increasing evidence has shown that chemoresistance is related to the process of epithelial-mesenchymal transition (EMT) and increased invasiveness by tongue squamous cell carcinoma (TSCC) cells. Long noncoding RNAs (lncRNAs) play pivotal roles in tumour metastasis and progression. However, the roles and mechanisms of lncRNAs in cisplatin resistance induced EMT and metastasis are not well understood. In this study, a Chemotherapy Induced Long non-coding RNA 1 (CILA1) was discovered by using microarrays and was functionally identified as a regulator of chemo-sensitivity in TSCC cells.Upregulation of CILA1 promotes EMT, invasiveness and chemoresistance in TSCC cells, whereas the inhibition of CILA1 expression induces MET and chemosensitivity and inhibis the invasiveness of cisplatin-resistant cells both in vitro and in vivo. We also found that CILA1 exerts its functions via the activation of the Wnt/ β-catenin signalling pathway.High CILA1 expression levels and low levesl of phosphorylated β-catenin were closely associated with cisplatin-resistance and advanced disease stage, and were predictors of poor prognosis in TSCC patients. These findings provided a new biomarker for the chemosensitivity of TSCC tumours and a therapeutic target for TSCC treatment.

Project description:Drug resistance poses a major challenge to ovarian cancer treatment. Understanding mechanisms of drug resistance is important for finding new therapeutic targets. In the present work, a cisplatin-resistant ovarian cancer cell line A2780-DR was established with a resistance index of 6.64. The cellular accumulation of cisplatin was significantly reduced in A2780-DR cells as compared to A2780 cells consistent with the general character of drug resistance. Quantitative proteomic analysis identified 340 differentially expressed proteins between A2780 and A2780-DR cells, which involve in diverse cellular processes, including metabolic process, cellular component biogenesis, cellular processes and stress responses. Expression levels of Ras-related proteins Rab 5C and Rab 11B in A2780-DR cells were lower than those in A2780 cells as confirmed by real-time quantitative PCR and western blotting. The short hairpin (sh)RNA-mediated knockdown of Rab 5C in A2780 cells resulted in markedly increased resistance to cisplatin whereas overexpression of Rab 5C in A2780-DR cells increases sensitivity to cisplatin, demonstrating that Rab 5C-dependent endocytosis plays an important role in cisplatin resistance. Our results also showed that expressions of glycolytic enzymes PKM, GPI, Aldolase, LDH, and PGK were down-regulated in drug resistant cells, indicating drug resistance in ovarian cancer is directly associated with a decrease in glycolysis. Furthermore, it was found that glutathione reductase were up-regulated in A2780-DR, while vimentin, HSP90, and Annexin A1 and A2 were down-regulated. Taken together, our results suggest that drug resistance in ovarian cancer cell line A2780 is caused by multifactorial traits, including the down-regulation of Rab 5C-dependent endocytosis of cisplatin, glycolytic enzymes and vimentin, and up-regulation of antioxidant proteins, suggesting Rab 5C is a potential target for treatment of drug-resistant ovarian cancer. This constitutes a further step towards a comprehensive understanding of drug resistance in ovarian cancer.

Project description:Tumor: tumor microenvironment (TME) interactions are critical for tumor progression and the composition and structure of the local extracellular matrix (ECM) are key determinants of tumor metastasis. We recently reported that activation of Wnt/beta- catenin signaling in Ewing sarcoma cells induces widespread transcriptional changes that are associated with acquisition of a metastatic tumor phenotype. Significantly, ECM protein-encoding genes were found to be enriched among Wnt/beta-catenin induced transcripts, leading us to hypothesize that activation of canonical Wnt signaling might induce changes in the Ewing sarcoma secretome. To address this hypothesis, conditioned media from Ewing sarcoma cell lines cultured in the presence or absence of Wnt3a was collected for proteomic analysis. Label-free mass spectrometry was used to identify and quantify differentially secreted proteins. We then used in silico databases to identify only proteins annotated as secreted. Comparison of the secretomes of two Ewing sarcoma cell lines revealed numerous shared proteins, as well as a degree of heterogeneity, in both basal and Wnt-stimulated conditions. Gene set enrichment analysis of secreted proteins revealed that Wnt stimulation reproducibly resulted in increased secretion of proteins involved in ECM organization, ECM receptor interactions, and collagen formation. In particular, Wnt-stimulated Ewing sarcoma cells upregulated secretion of structural collagens, as well as matricellular proteins, such as the metastasis-associated protein, tenascin C (TNC). Interrogation of published databases confirmed reproducible correlations between Wnt/beta-catenin activation and TNC and COL1A1 expression in patient tumors. In summary, this first study of the Ewing sarcoma secretome reveals that Wnt/beta-catenin activated tumor cells upregulate secretion of ECM proteins. Such Wnt/beta-catenin mediated changes are likely to impact on tumor: TME interactions that contribute to metastatic progression.

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	GSE267752_normalized_count_matrix.xlsx	Xlsx

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Mechanistic Insights into Epithelial-Mesenchymal Transition Mediated Cisplatin Resistance in Ovarian Cancer

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