【摘要】 目的研究垂体肿瘤转化基因1(Pituitary Tumor Tansforming Gene1,PTTG1)过表达对人结肠癌细胞SW480增殖和周期的影响及其可能机制。方法采用脂质体转染法将pc DNA3.1(+)-PTTG1及空载pc DNA3.1(+)质粒转染人结肠癌SW480细胞,G418法筛选阳性克隆。Western blot法检测PTTG1和cyclin D、cyclin E、p21的表达。MTT法检测细胞增殖,流式细胞术检测细胞周期。结果 (1)成功获得PTTG1高表达的SW480细胞pc DNA3.1(+)-PTTG1及对照pc DNA3.1(+)细胞,Western blot结果显示pc DNA3.1(+)-PTTG1细胞PTTG1表达量分别为pc DNA3.1(+)细胞和SW480细胞的3.58倍和3.42倍;(2)过表达PTTG1基因后,SW480细胞周期改变,G0/G1期细胞减少而S期和G2/M期细胞增加;细胞周期调控蛋白cyclin D和cyclin E表达升高,p21表达降低;SW480细胞增殖显著性加快。(3)过表达PTTG1基因后,SW480细胞中PI3K/AKT信号活化增强,使用PI3K/AKT信号抑制剂LY29400干预后,细胞增殖减弱,周期蛋白cyclin D和cyclin E表达降低,p21表达升高。结论 PTTG1基因过表达可能通过活化PI3K/AKT信号加速SW480细胞从G1期向S期的转化促进细胞增殖,提示PTTG1蛋白可能成为结肠癌治疗的一个潜在靶点。更多还原

【Abstract】 Objective The aim of this study was to evaluate the effect of pituitary tumor transforming gene 1 on the proliferation and cycle of human colon cancer cell line SW480 and its possible mechanism. Methods Both pc DNA3.1(+)-PTTG1 and pc DNA3.1(+) plasmids were separately transfected into human colon cancer cell line SW480 cells by liposome transfection method and G418 was used to screen positive clones. The expression of PTTG1, cyclin D, cyclin E and p21 were detected by western blotting. Cell proliferation was detected by MTT assay, and cell cycle was detected by flow cytometry.Results 1) Both pc DNA3.1(+)-PTTG1 and pc DNA3.1(+) cells were successfully obtained. The expression of PTTG1 in pc DNA3.1(+)-PTTG1 cells were 3.42 times in SW480 cells and 3.58 times in pc DNA3.1(+) cells, respectively. 2) After PTTG1 over-expression, the cell cycle of SW480 cells were changed. The ratio of G1/G0 cell cycle was significantly decreased and S and G2/M cell cycle were dramatically increased. Cyclin D and cyclin E expression were up-regulated. The expression of p21 was down-regulated, and the proliferation SW480 cells were significantly increased. 3) The signaling pathway of PI3K/AKT activation was enhanced in pc DNA3.1(+)-PTTG1 cells, interfering with LY29400. The inhibitor of PI3K/AKT, the proliferation of pc DNA3.1(+)-PTTG1 cells was decreased. The expression of cyclin D and cyclin E were decreased and p21 expression was increased in pc DNA3.1(+)-PTTG1 cells. Conclusion PTTG1 over-expression may promote SW480 cells proliferation through accelerating conversion from G1 phase to S phase by activating PI3K/AKT pathway. PTTG1 may become a potential target for colon cancer treatment.更多还原