抑制自噬促进MK-2206诱导SGC-7901胃癌细胞发生DNA损伤

目的:探讨蛋白激酶B(protein kinase B,Akt)抑制剂MK-2206对胃癌细胞SGC-7901DNA损伤的影响。方法:不同浓度的MK-2206作用于SGC-7901细胞后,免疫荧光检测细胞内DNA损伤标记分子磷酸化组蛋白H2AX(γ-H2AX)焦点的生成,Western blot检测DNA损伤相关蛋白的表达水平,同时观察MK-2206对自噬标志蛋白LC3-II表达量的影响,用以确定MK-2206是否促进细胞发生自噬。结果:MK-2206能够诱导SGC-7901细胞发生DNA损伤,促进细胞内γ-H2AX焦点生成,并且激活DNA损伤相关蛋白的表达;MK-2206作用细胞后,LC3-II的生成增加;抑制细胞的自噬显著增强了MK-2206诱导的H2AX磷酸化水平。结论:Akt抑制剂MK-2206能够诱导细胞发生DNA损伤和自噬,抑制自噬促进了MK-2206诱导的DNA损伤。

Blocking autophagy magnifies MK-2206-induced DNA damage in SGC-7901 cells

AIM: To investigate the effect of MK-2206, an inhibitor of protein kinase B(Akt), on the DNA damage of SGC-7901 cells.METHODS: SGC-7901 cells were treated with different concentrations of MK-2206, and phosphorylated histone H2AX(γ-H2AX) foci formation was detected by immunofluorescence staining. Western blot analysis was used to exam the levels of DNA damage-related protein. The expression of LC3-Ⅱ was determined to evaluate the change of autophagy.RESULTS: MK-2206 treatment increased the formation of γ-H2AX foci and histone H2AX phosphorylation in the SGC-7901 cells. The levels of DNA damage response protein were also increased. In addition, MK-2206-treated SGC-7901 cells increased the expression of LC3-II, a hallmark of autophagy. Inhibition of autophagy significantly enhanced MK-2206-mediated histone H2AX phosphorylation.CONCLUSION: MK-2206 induces DNA damage and autophagy in SGC-7901 cells. Blocking autophagy potentiates the response of MK-2206-induced DNA damage.