JNK通路在高糖促人乳腺癌MCF-7细胞增殖中的作用

Role of JNK signaling pathway in the proliferation of human breast cancer cell line MCF-7 induced by high glucose

目的探讨c-Jun氨基末端激酶(JNK)信号通路在高糖促进人乳腺癌MCF-7细胞增殖中的作用。方法体外培养人乳腺癌MCF-7细胞,分为低糖组(葡萄糖浓度为5.5mmol/L);高糖组(葡萄糖浓度为25 mmol/L);加药组:高糖+不同浓度特异性JNK信号转导通路抑制剂SP600125(10、20、40、80μmol/L)。四亚基偶氮唑盐(MTT)比色法检测各组作用24、48、72 h细胞增殖水平;倒置显微镜下观察细胞形态;Annexin V-FITC/PI染色结合流式细胞技术检测作用24 h后细胞凋亡率;Western blot检测作用24 h后细胞内JNK1/2及磷酸化JNK1/2(p-JNK1/2)蛋白的表达水平。结果①MTT检测结果显示:与低糖组比较,高糖能够促进MCF-7细胞增殖(P<0.05),SP600125可以抑制高糖对MCF-7细胞的促增殖作用(P<0.05);②凋亡检测结果显示:低糖组与高糖组凋亡率差异无统计学意义,SP600125呈浓度依赖性促进高糖环境下MCF-7细胞的凋亡(P<0.05);③Western blot检测结果显示:与低糖组比较,高糖组MCF-7细胞p-JNK1/2蛋白表达量增加(P<0.05),且p-JNK/JNK比值上升(P<0.05);与高糖组相比,不同浓度的SP600125可以明显降低p-JNK1/2蛋白的表达(P<0.05),并下调pJNK/JNK的比值(P<0.05)。结论抑制JNK信号通路后可以抑制高糖所诱导的MCF-7增殖,并诱导其凋亡。

Objective To investigate the role of c-Jun N-terminal kinase （JNK） signaling pathway in the prolifera- tion of human breast carcinoma cell line MCF-7 induced by high glucose. Methods MCF-7 cells were cultured in vitro and then treated with SP600125, a specific JNK inhibitor. The experiment was divided into low glucose group, and high glucose group, high glucose ＋ 10 μmol/L SP600125 group, high glucose ＋ 20μmol/L SP600125 group, high glucose ＋ 40 μmol/L SP600125 group, and high glucose ＋ 80 μmol/L SP600125. The cell growth inhibitory rate was detected by Methyl thiazolyl tetrazolium （MTT） assay; the cell morphological changes were observed by invert microscope; the apoptosis rate was analyzed by using Annexin V-FITC/PI fluorescence staining together with flow cytometry; the expressions of JNK1/2 and p-JNK1/2 were examined by Western blot. Results High glucose could promote the proliferation of MCF-7 cells compared with low glucose group （P 〈 0. 05）. Western blot implicated that high glucose increased the the expressions of p-JNK and p-JNK/JNK compared with low glucose （P 〈 0. 05 ）.SP600125 remarkably inhibited the activation of JNK1/2 and increased the cell growth inhibitory rate and apoptosis rate in MCF-7 cells induced by high glucose compared with those treated with high glucose only. Conclusion High glucose can stimulate the proliferation of MCF-7 ceils in vitro. Inhibition of JNK signaling pathway in MCF-7 cells can significantly inhibite cell proliferation and promote apoptosis. JNK signaling pathway may play an impor- tant role in the high glucose-induced proliferation of MCF-7 ceils.