PTEN在白藜芦醇对体外直肠癌细胞生长和凋亡的影响

分析第10号染色体同源丢失性磷酸酶张力蛋白基因(phosphatase and tensin homology deleted on chromosome ten,PTEN)在直肠癌细胞系中的相对表达水平,以及白藜芦醇对直肠癌细胞增殖和凋亡的作用,并分析其可能作用机制。利用Western blot检测PTEN在人直肠癌细胞株Caco-2和SW480及人正常结肠上皮细胞株NCM460中的表达;不同浓度的白藜芦醇作用体外SW480细胞后,CCK-8法检测白藜芦醇对细胞增殖的影响;流式细胞术检测白藜芦醇对细胞凋亡的影响;Western blot检测Caspase-3,PTEN,p53以及AKT蛋白在SW480细胞中的表达水平;构建慢病毒介导特异性短发夹RNA(short hairpin RNA,shRNA)下调SW480细胞中PTEN的表达,检测下调PTEN的表达后是否影响白藜芦醇对体外直肠癌细胞的生长抑制和凋亡诱导作用。结果表明,与NCM460细胞相比较,PTEN在Caco-2和SW480中的表达量均显著下调,差异有统计学显著性(P0.001);白藜芦醇对体外直肠癌SW480细胞增殖有明显抑制作用,并诱导细胞凋亡;白藜芦醇对SW480细胞中Caspase-3,PTEN和p53蛋白的表达均有明显上调作用,而抑制磷酸化AKT的表达;shRNA PTEN可明显下调PTEN在SW480细胞中的表达,同时降低白藜芦醇对SW480细胞的增殖抑制和凋亡诱导作用。提示白藜芦醇可通过上调PTEN的表达从而调控体外直肠癌细胞增殖和凋亡。

Effect of resveratrol in regulating proliferation and apoptosis of rectal cancer cells via up-regulating PTEN

To analysis the relative expression of PTEN(phosphatase and tensin homology deleted on chromosome ten) in rectal cancer cell lines and the effects of resveratrol on cell proliferation and apoptosis of rectal cancer cells in vitro. Western blot was used to assess the protein expression of PTEN in rectal cancer cell lines and non-malignant colon epithelial cell line. After treating human rectal cancer cell line SW480 with different concentrations of resveratrol, the cellular proliferation was detected by cell counting Kit-8(CCK-8) assay. The apoptotic rate was analyzed by flow cytometry. The protein expressions of Caspase-3, PTEN, p53 and phosphorylase AKT(p-AKT) were detected by Western blot. shRNA(short hairpin RNA) was built to down-regulate PTEN expression in SW480 cells, and detect whether the own-regulated PTEN expression impact resveratrol''s effect in growth inhibition and apoptosis induction of in vitro rectal cancer cells. Our results demonstrated that the relative level of PTEN was markedly decreased in Caco-2 and SW480, with statistically significant differences(P<0.001). Resveratrol inhibited the proliferation of rectal cancer cells markedly, and triggered apoptosis of SW480 cells. The protein expressions of Caspase-3, PTEN and p53 were all increased after being treated with resveratrol, while the expression of p-AKT was decreased after the treatment. The expression of endogenous PTEN was significantly decreased in shRNA PTEN-infected SW480 cells. Meanwhile, shRNA PTEN could obviously reduce SW480 cells'' anti-proliferative and apoptotic effects. The experimental results suggested that resveratrol can be used as an anti-proliferative and apoptosis induction agent in rectal cancer through up-regulation of PTEN.