染色体缺失磷酸酶及张力蛋白同源物对胰腺癌细胞系细胞周期和增殖能力的影响

目的探讨10号染色体缺失的磷酸酶及张力蛋白同源物(PTEN)对胰腺癌细胞质(ASPC-1)血管内皮生长因子(VEGF)蛋白表达、细胞周期和增殖的影响.方法将质粒pEAK8-PTEN和pEAK8分别转染指数生长期的胰腺癌细胞株(ASPC-1),挑选阳性细胞克隆,扩增培养,用RT-PCR、Western印迹、流式细胞术、生长速率等方法分别检测PTEN对ASPC-1细胞VEGF蛋白、细胞周期及增殖能力的影响.结果ASPC-1细胞转染后,PTEN mRNA表达量是转染前的3倍;ASPC-1、ASPC-1-pEAK8、ASPC-1-pEAK8-PTEN细胞PTEN蛋白表达量分别为13.2、12.6和21.6,VEGF蛋白表达量分别为17.2、16.5和13.1,转染后较转染前降低.细胞周期显示,ASPC-1-pEAK8-PTEN细胞较ASPC-1、ASPC-1-pEAK8细胞G2/M、S期细胞增多,Gl期细胞减少,并出现少量凋亡细胞(P＜0.01).ASPC-1-pEAK8-PTEN细胞生长曲线平缓,生长速度较另两种细胞明显降低.结论 PTEN可使ASPC-1细胞VEGF蛋白表达下降,细胞阻滞在G2/M期,抑制肿瘤细胞增殖.

Effect of phosphatase and tensin homologue deleted on chromosome ten on the cell cycle and proliferation of pancreatic cancer cell line

Objective To investigate the effect of phosphatase and tensin homologue deleted on ~chromosome ten (PTEN) on cell cycle, expression of vascular endothelial growth factor (VEGF) and ~proliferation in a human pancreatic cancer cell line (ASPC-1). Methods The pancreatic cancer ASPC-1 cell was transfected with an eukaryotic expression plasmid (pEAK8) inserted PTEN or not in vitro by ~lipofectin methods, and positive cell clones were selected and amplified. Effects of PTEN on ASPC-1 cells were measured by flow cytometry, Western blot and tumor growth curve. Results PTEN mRNA ~expression in the ASPC-1-pEAK8-PTEN cell was two fold up than that in ASPC-1 cells. PTEN and VEGF protein expressions in the ASPC-1, ASPC-1-pEAK8 and ASPC-1-pEAK8-PTEN cells were 13.2, 12.6, 21.6 and 17.2, 16.5, 13.1, respectively. It was found that PTEN protein could be much more ~efficiently expressed in transfected ASPC-1 cell contained plasmid pEAK8-PTEN, whereas the expression of VEGF protein decreased comparing with ASPC-1 or ASPC-1-pEAK8 cell. In addition, in ASPC-1 cells carrying exogenous PTEN, apoptosis cells, and the cells in S and G2/M phase increased whereas G1 phase cells decreased (P<~0.01 ). The growth of cell transfected with PTEN was dramatically ~inhibited compared with the parent ASPC cell or ASPC-1-pEAK8 cell. Conclusion The findings suggest ~that exogenous PTEN inhibit ASPC-1 cell growth by increasing PTEN and decreasing VEGF expression, which led to the ASPC-1 cells in G2/M phase increase.