橘红素上调Cyclin B1和抑制ERK磷酸化诱导人胃癌AGS细胞周期阻滞

Arrest of human gastric cancer AGS cells by tangeretin via CyclinB1 upregulation and inhibition of ERK phosphorylation

目的探讨橘红素对人胃癌AGS细胞增殖和周期的作用及其机制。方法采用MTT法观察橘红素对人AGS胃癌细胞增殖的作用;流式细胞仪检测橘红素对细胞周期的影响;Western blot检测橘红素对Cyclin B1、Cyclin D1、Cyclin E1和ERK、p-ERK蛋白表达的影响。结果橘红素可明显抑制AGS胃癌细胞的增殖(P<0.01),呈时间和剂量依赖性。橘红素作用于AGS细胞24 h,S期细胞百分比明显增高,与对照组比较差异有统计学意义(P<0.01);作用48和72 h,S期阻滞消失,G2/M期细胞百分比增高(P<0.05,P<0.01)。作用48 h,橘红素可上调Cyclin B1蛋白的表达(P<0.05,P<0.01),对Cyclin D1和Cyclin E1蛋白表达无明显影响;对ERK蛋白表达无影响,可降低p-ERK蛋白的表达(P<0.01),且呈剂量依赖性。结论橘红素可明显抑制人AGS胃癌细胞的增殖,使细胞阻滞于S期和G2/M期,主要机制可能是通过抑制ERK磷酸化和上调CyclinB1蛋白表达。

Aim To study the effects of tangeretin on proliferation and cell cycle of human AGS gastric cancer cells and its mechanisms.Methods MTT assay was used to detect the growth inhibition rates of human AGS gastric cancer cells treated with tangeretin.The cell cycle distribution was measured by flow cytometry.The protein expressions of Cyclin B1,Cyclin D1,Cyclin E1,ERK and p-ERK were detected by western blot.Results MTT assay showed tangeretin inhibited the growth of AGS gastric cancer cells in a time-and dose-dependent manner（P 0.01）.Tangeretin arrested AGS cells in S phase compared with control group for 24 h（P 0.01）.After treatment with tangeretin for 48 h and 72 h,AGS cells were arrested in G2 / M phase（P 0.05,P 0.01）.Western blot showed that tangeretin increased the expression of Cyclin B1 protein in a dose-dependent manner（P 0.05,P 0.01）,but had no effects on that of Cyclin D1 and Cyclin E1.ERK was not changed and p-ERK was downregulated after treatment with tangeretin（P 0.01）.Conclusion Tangeretin can inhibit proliferation of human AGS gastric cancer cells and induce cell cycle arrest in S and G2 / M phases.The inhibition of ERK phosphorylation and upregulation of Cyclin B1 protein might be one of the mechanisms.