| Pancreatic cancer is one of the most lethal malignancies in modern society, its morbidity and mortality are now rising trend no matter at home and abroad. And it had a poor prognosis. Pancreatic cancer have the worst prognosis because of its insidious onset and rapid progression, which is very difficult in the early detection and early intervention. Most patients are not diagnosed until the cancer has metastasized to other organs. That is why the metastasis is a major problem during pancreatic cancer treatment. The metastasis of pancreatic cancer is a complicated process composed of various factors. And the specific mechanism has not been completely elucidated. There is an urgent need to define the specific pathogenesis of pancreatic cancer in the molecular aspect and to further find the appropriate way of intervention and molecular targeted therapy.Long non-coding RN As(lnc RN As) are non-protein coding transcripts longer than 200 nucleotides, regulate the expression of gene on multiple levels, involved in varies of physiological processes included embryonic developme nt, cell growth, differentiation and metabolism. A recent study found that lnc RNA in cancer cells have abnormal increase or reduce performance, which promote or inhibit tumor occurrence and development, similar to the oncogenes or tumor suppressor genes.PCGEM1, a prostate-specific gene, was found to be higher in prostate cancer LNCa P cell and mouse fibroblasts NIH3T3 cells. In humans, it is located on chromosome 2q32, could promote prostate cancer cell proliferation, migration, invasion, and inhibit the apoptosis of tumor cells. Also it could be used as a reliable indicator for evaluating the risk and prognosis of prostate cancer, is a potential drug target for prostate cancer gene therapy.Objective: 1. To investigate the expression of PCGEM1 in pancreatic carcinoma and its role in the biological behavior of pancreatic cancer cells. 2. To explore the underlying molecular mechanisms, and provide a theoretical basis for the clinical treatment of pancreatic cancer gene therapy.Methods: 1. The expression level of PCGEM1 in 3 different pancreatic cancer cell lines and in human pancreatic cancer tissues and their adjacent non-cancer tissues were detected by real-time PCR. 2. The effect of PCGEM1 on cell proliferation, migration and invasion ability was detected after up regulation or down regulation of PCGEM1 expression in pancreatic cancer cel s. 2.1 The p CDH-PCGEM1 was transfected into either Bx PC3 or Pa Tu8988 to increase the expression level of PCGEM1. Meanwhile, SW1990 transfected with si RN A to decrease the expression level of PCGEM1, and the transfection efficiency was detected. 2.2 The abilities of the proliferation was determined using clone formation assay and CCK-8 assay. 2.3 The abilities of the migration and invasion were determined by transwell assay. 3. To detect the changes of EMT related protein and TGF-β/smad pathway related protein after up regulation or down regulation of PC GEM1 expression in pancreatic cancer cel s. 3.1 The protein levels of EMT related protein were examined by Western blot and cell immunofluorescence staining, and the m RNA levels of MMP2 and MMP9 were detected by real-time PCR. 3.2 Expression level of TGF-β/smad pathway related protein was examined by Western blot.Results: 1. There were significant differences of PCGEM1 expression level in three kinds o f human pancreatic cancer cell lines. The expression level of PCGEM1 in SW1990 was relatively high, compared with which was in Bx PC3 and Pa Tu8988. The level of PCGEM1 in pancreatic cancer tissues was higher than that in adjacent non-cancer tissues. 2. PCGEM1 overexpression promotes the proliferation, migration and invasion of human pancreatic cancer cel s.2.1 Successful up regulation of PCGEM1 expression in Bx PC3 and Pa Tu8988 cells, and down regulation of PCGEM1 expression in SW1990 cells. 2.2 It was shown that the o verexpression of PCGEM1 stimulated proliferation in vitro. In contrast, knockdown of PCGEM1 suppressed these processes. 2.3 The expression level of PCGEM1 was positively correlated with the migration ability of human pancreatic cancer cells. 3. PCGEM1 promotes the EMT process through the /smad beta TGF- pathway. 3.1 PCGEM1 overexpression elevated the expression of collagen ?, α-SMA and Vimentin, while decreased E-cadherin expression. And while we knockdown the expression of PCGEM1, we get the opposite result. Beside, after up regulation of PCGEM1, the expressions of protein and m RNA of MMP2 and MMP9 increased significantly. Conversely, the expression of protein and m RNA of MMP2 and MMP9 decreased after down regulation of PCGEM1 which detected by RT-q PCR and western blot. 3.2 Overpression PCGEM1 could significantly increase phosphorylated Smad2/3 change. Meanwhile, the TGF-β and TGF-β receptor protein level were markedly changed, they were positively correlated with the expression level of PCGEM1. Whereas, protein level of S mad4 was negatively correlated with the expression level of PCGEM1. The trends of Smad2/3, p Smad2/3, Smad4, TGF-β and TGFR were nearly the reverse as that of PCGME1 knockdown cel s.Conclusion: 1. PCGEM1 is relatively highly expressed in pancreatic cancer tissues, and is differentially expressed in different pancreatic cancer cell lines. 2. PCGEM1 promotes the proliferation, migration and invasion of pancreatic cancer cel s. 3. PCGEM1 can promote the EMT process of pancreatic cancer cells by regulating the TGF- β /smad pathway. |
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