Influence Of DPC4 Gene On The Growth And Proliferation Of Pancreatic Cancer Cells JF305

Objective Pancreatic adenocarcinoma is one of the commonent malignancies with an overall 5-year survival rate of less than 5% and 80% patients with pancreatic cancer metastasis at diagnosis. It has been shown that the development and progression of pancreatic cancer was accompanied by alterations of many genes such as K-ras, p53, p16 and DPC4. Recent study showed that the devitalization of DPC4 gene was present in nearly 50% of pancreatic carcinoma, which interrupted the TGF-βsignal pathway, so inactivation of DPC4 gene maybe one of the most important cause of pancreatic carcinoma. The present study was carried out to clarify the effect of DPC4 gene on human pareatic carcinoma cell line JF305, which can help us understand the growth and proliferation mechanism of pancreatic carcinoma and provide us the practical guidance on gene therapy of pancreatic carcinoma.Methods The full length coding sequence of DPC4 gene was transfected into human pancreatic adenocarcinoma cell line JF305The transfection was done by using lipofectamine transfecting techniqueStable transfectants were obtained through G418(400ug/ml) selective culture for five weeksThe cells not transfected and transfected pBK-CMV plasmid were used as controls.The expression of DPC4 was detected by RT-PCR.The cell growth rate was estimated by cell count and MTT methodCell cycle was assessed by flow cytometryThe changes of the biological behaviors of the JF305 cell transfected with pBK-CMV-DPC4 plasmid and pBK-CMV plasmid and without transfection were evaluated by sticking and cloning efficiency.Results Only JF305 cells transfected with pBK-CMV-DPC4 plasmid and pBK-CMV plasmid still survived after selected culturing with G418 JF305 cells transfected with pBK-CMV-DPC4 plasmid strongly expressed the DPC4, while its expression in JF305 cells transfected with pBK-CMV and JF305 cells not transfected could not be detected. After being transfected with pBK-CMV-DPC4the proliferation of JF305 cells was suppressed markedly wthich was demonstrated both by MTT and cell count assay. The population doubling time in JF305 cells transfected with pBK-CMV-DPC4 plasmid was much longer than that in JF305 cells without transfection. Compared with JF305 cells without transfection and transfected with pBK-CMV plasmid, the cells of G1 phase of JF305 cells transfected with pBK-CMV-DPC4 plasmid increased while the cell number of G2/M phase decreased significantly. The cloning and sticking efficiencies of JF305 cells transfected with pBK-CMV-DPC4 plasmid were significantly different from that of JF305 cells without transfection and transfected with pBK-CMV plasmid.Conclusion DPC4 had been successfully transfected into JF305 cells and the transfected cell line could express the DPC4 steadily resulting in the increase of G1 phase cells and decrease of G2/M phase cells in JF305 cells. DPC4 gene could also inhibit the growth and proliferation of human Pancreatic adenocarcinoma cell line JF305. This indicated that there might be a close relationship between absence of DPC4 gene and pathogenesis of pancreatic carcinoma. The alteration of the tumor suppressor gene DPC4 might be an important molecular event in pancreatic carcinoma and probably plays a crucial role in its development and progression. DPC4 gene might become one of the target genes for Pancreatic adenocarcinoma gene therapy.