FoxO1过表达对甲状腺乳头状癌细胞增殖、凋亡和细胞周期的影响及其机制

Effects of FoxO1 over-expression on proliferation,apoptosis,and cell cycle of PTC cells

目的观察转录因子叉头框蛋白O1(FoxO1)过表达对甲状腺乳头状癌(PTC)细胞增殖、凋亡和细胞周期的影响,并探讨其机制。方法人PTC细胞株KTC-1分为对照组和过表达组。对照组细胞感染空载体慢病毒pLV-Control,过表达组细胞感染FoxO1过表达慢病毒pLV-FoxO1。确定稳定转染并继续培养48 h后,采用MTT法及克隆形成实验检测细胞增殖能力;流式细胞术检测凋亡细胞及细胞周期分布;Western blotting法检测细胞中的磷脂酰肌醇3激酶(PI3K)、蛋白激酶B(Akt)、p-Akt、Bim蛋白。结果与对照组相比,过表达组细胞增殖率及克隆形成数降低,细胞凋亡率增加,G 0/G 1期细胞比例增多(P均<0.05);过表达组细胞中PI3K蛋白表达及p-Akt/Akt水平低于对照组,Bim蛋白表达高于对照组(P均<0.05)。结论FoxO1过表达可抑制PTC细胞增殖,促进其凋亡,并使细胞周期阻滞于G 0/G 1期;其作用机制可能与调控PI3K/Akt/Bim信号通路相关。

Objective To observe the effects of transcription factor Forkhead box protein O1(FoxO1)over-expression on the proliferation,apoptosis,and cell cycle of papillary thyroid carcinoma(PTC)cells,and to investigate the mechanism.Methods Human PTC cell line KTC-1 was divided into the control group and over-expression group.Cells in the control group were transfected with empty vector lentivirus(pLV-control),while cells in the over-expression group were transfected with FoxO1 over-expressed lentivirus(pLV-FoxO1).After stable transfection and continuous culture for 48 h,MTT assay and clone formation assay were used to detect cell proliferation capacity.Flow cytometry was used to detect apoptotic cells and cell cycle distribution.Western blotting was used to detect phosphatidylinositol 3 kinase(PI3K),protein kinase B(Akt),p-Akt and Bim protein in the cells.Results Compared with the control group,the cell proliferation rate and the number of clone formation decreased significantly,the cell apoptosis rate increased,and the proportion of cells in the G 0/G 1 phase cells increased in the over-expression group(all P<0.05).The expression level of PI3K protein and p-Akt/Akt in cells of the over-expression group was lower than that of the control group,and the expression level of Bim protein was higher than that of the control group(both P<0.05).Conclusion FoxO1 over-expression may inhibit the proliferation and apoptosis of PTC cells,and lead to cell cycle arrest in the G 0/G 1 phase by regulating the PI3K/Akt/Bim signaling pathway.