自噬相关蛋白5通过p53/p21通路调控结肠癌细胞衰老

Autophagy Related Protein 5 Regulates Colon Cancer Cell Senescence Through p53/p21 Pathway

目的探讨ATG5在结肠癌HT29细胞中对细胞衰老和增殖的影响。方法多柔比星诱导细胞衰老,免疫印迹法检测ATG5在衰老细胞中的蛋白表达量。瞬时转染siRNA低表达ATG5,β-半乳糖苷酶染色和CCK8法分别检测衰老细胞比例及细胞增殖能力;同时加入雷帕霉素(Rapa)诱导自噬,检测细胞发生衰老比例及各组细胞增殖能力变化。蛋白免疫印迹技术检测ATG5对细胞衰老相关通路蛋白P53以及P21的影响。结果多柔比星诱导细胞衰老可下调ATG5的蛋白表达。SiNC对照组细胞发生衰老细胞数平均值为3±1,SiATG5组发生衰老细胞数平均值为12±2,低表达ATG5加Rapa组发生衰老细胞数平均值为12±1,低表达ATG5后可上调衰老相关蛋白P53和P21的表达。结论ATG5调控衰老的作用不依赖于自噬,而通过p53/p21通路调控结肠癌细胞衰老。

Objective To investigate the effect of ATG5 on the senescence and proliferation of colon cancer HT29 cell line.Methods The senescence of colon cancer HT29 cell line was induced by doxorubicin.ATG5 expression was detected by Western blot.Low expression of ATG5 was detected by transient transfection of small interfering RNA,and the proportion of cell senescence and proliferation ability were detected by beta-galactosidase staining and CCK assay,respectively.At the same time,we added Rapa to induce autophagy and detected the proportion of cell senescence and proliferation ability.The effect of ATG5 on cell senescence related pathway proteins P53 and P21 was detected by Western blot.Results The protein expression of ATG5 was down-regulated by doxorubicin-induced cell senescence.The mean number of senescent cells in the SiNC control group was 3±1,while that in the SiATG5 group was 12±2,and that in the low-expression ATG5 plus Rapa group was 12±1.Low expression of ATG5 could up-regulate the expression of senescence-related proteins P53 and P21.Conclusion Down-regulation of ATG5 promotes the senescence of colon cancer cells by up-regulating p53/p21.