| Pancreatic cancer is one of the most malignant tumors of digestive system. As a result of difficult to early diagnose, most of the patients are not diagnosed until advanced stage and metastasis have occurred. Due to the poor prognosis, the 5-year survival rate is less than 5%. Currently, the pathogenesis mechanism of pancreatic cancer is not clear, which largely prevent the development of pancreatic cancer therapy. Therefore, there is an urgent need to investigate the molecular mechanism of pancreatic cancer, which is helpful for early diagnosis, targeted therapy and evaluation of prognosis of pancreatic cancer.Long non coding RNA(lnc RNA) is a kind of non-protein-coding RNA which transcription length exceeds 200 nt. Emerging studies have indicated that lnc RNA involved in diverse regulatory roles in epigenetic, chromatin modifications, transcriptional regulation. Therefore, lnc RNA plays important biological functions in the process of the occurrence and development of disease, particularly affects tumor cell growth, apoptosis and metastasis.Plasmacytoma variant translocation 1(PVT1) is a specific lnc RNA. Recently, increasing evidences have shown that PVT1 as a tumor specific gene play pivotal roles in prostate cancer, lung cancer, liver cancer, colorectal cancer, gastric cancer and other tumors, involved in tumor cell proliferation, apoptosis, invasion and metastasis, stem cell differentiation and drug resistance. However, the molecular mechanisms of PVT1 in pancreatic cancer have still not been elucidated.1. Differential expression of long non-coding RNA PVT1 in pancreatic cancer tissues and pancreatic cancer cellsObjective: To explore the expression level of PVT1 in pancreatic cancer tissues and pancreatic cancer cells, and lay foundation for following experiments.Methods: 1. q RT-PCR was used to detect the PVT1 expression in cancer tissues and adjacent tissues of nine pancreatic cancer patients.2. q RT-PCR was used to detect the PVT1 expression in four pancreatic cancer cell lines.Results: 1. The expression of PVT1 in cancer tissues were higher than adjacent tissues among nine pancreatic cancer patients. 2. Among the four pancreatic cancer cell lines, the expression of PVT1 in Pa Tu8988 was the highest, Bx PC-3 was taken the second place and SW1990 was the lowest.Conclusion: The abnormal expression of PVT1 in pancreatic cancer tissues indicate that PVT1 may play a potential role in pancreatic cancer. We also find that the expression of PVT1 is positive correlation with the malignant degree in four pancreatic cancer cell lines, so its function need further study.2. The study of biological function of long non-coding RNA PVT1 in pancreatic cancer cell linesObjective: To explore the biological role of PVT1 in pancreatic cancer tissues and pancreatic cancer cells.Methods: Small interfering RNA and PVT1-plasmid were used to knockdown the PVT1 expression level of Pa Tu8988 and Bx PC-3, and overexpress the PVT1 level of SW1990. Cell proliferation assay, Flow Cytometry, adhesion assay and Transwell assay were used to detect the ability of cell proliferation, apoptosis, adhesion and invasion.Results: Cell proliferation assay, cell adhesion assay, transwell assay showed that down-regulated PVT1 expression significantly decreased the ability of cell proliferation, adhesion and invasion and metastasis of Pa Tu8988 and BXPC-3, however, up-regulated PVT1 expression significantly increased the ability of cell proliferation, adhesion and invasion and metastasis of SW1990. Flow Cytometry showed that down-regulation PVT1 expression significantly promote cells apoptosis of Pa Tu8988 and BXPC-3, up-regulation PVT1 expression significantly inhibited SW1990 cell apoptosis.Conclusion: PVT1, an oncogene of pancreatic cancer, can enhance the ability of cell proliferation, adhesion, invasion and metastasis of pancreatic cancer cells, and inhibit the cell apoptosis. However, the molecular mechanism of PVT1 in pancreatic cancer need further study.3. The study of molecular mechanism of long non-coding RNA PVT1 in pancreatic cancerObjective: To explore the underlying molecular mechanism of PVT1 in pancreatic cancer.Methods: 1. Western Blot was used to detect the protein level of MMP2 and MMP9. 2. Western Blot was used to detect the protein level of Caspase3, Bax and Bcl-2. 3. Western Blot was used to detect the level of epithelial mesenchymal transition related proteins, such as E-cadherin, N-cadherin, Vimentin, β-catenin, Snail and Slug. 4. Western Blot was used to detect the level of TGFβ/smad signaling pathway cascade, including smad2/3, p- smad2/3, smad4 and TGFβ1.Results: 1. Knockdown of PVT1 reduced Matrix metalloproteinases MMP2 and MMP9, while, up-regulation of PVT1 increased them. 2. Knockdown of PVT1 reduced apoptosis related protein including Caspase3 and Bcl-2, while it induced Bax. And, ectopic expression of PVT1 reversed the process. 3. Knockdown of PVT1 reduced EMT marker genes including snail, slug, β-catenin, N-cadherin, and Vimentin, while it induced E-cadherin. And, ectopic expression of PVT1 reversed the process. 4. Knockdown of PVT1 impacted the TGF-β/smad signaling cascade, decreasing p-smad2/3, TGF-β1 and increasing smad4. In contrast, ectopic expression of PVT1 reversed the process.Conclusion: These findings suggest that PVT1 acts as an oncogene in pancreatic cancer, possibly through regulation of EMT via TGF-β/smad signaling pathway. |
PDF Full Text Request