氯尼达明诱导乳腺癌MCF-7细胞凋亡的作用及机制

摘要

Objective To investigate the effect of lonidamine on apoptosis of human breast carcinoma cells MCF-7 and the possible mechanisms. Methods MTT assay and colony-forming assay were used to evaluate the growth inhibition induced by lonidamine in breast cancer MCF-7 cells. PI/Annexin-V staining was used to detect the apoptotic cells. The ATP levels in the cells were detected using an ATP assay kit. The expression of glucose regulated protein 78 (GRP78), inhibitor of apoptosis protein (cIAP1) and caspase-8 were analyzed with Western blotting. Results MTT assay and colony-forming assay showed that 50-250 mmol/L lonidamine caused a time- and concentration-dependent inhibition of MCF-7 cell proliferation. Exposure to increased concentrations of lonidamine resulted in significantly increased apoptosis rate in MCF-7 cells. In MCF-7 cells treated with 50, 150 and 250 mmol/L lonidamine for 5 h, the intracellular ATP levels were lowered to 80.67%, 62.78%and 30.73%of the control level, respectively. Western blotting showed that lonidamine up-regulated the expression of GRP78, down-regulated the expression of cIAP1 and promoted caspase-8 activation as the treatment time extended. Conclusion Lonidamine can inhibit the proliferation and induce apoptosis in MCF-7 cells, and these effects are probably mediated by reducing ATP level, inducing endoplasmic reticulum stress response, down-regulating cIAP1, and promoting caspase-8 activation in the cells.%目的：探讨氯尼达明诱导人乳腺癌MCF-7细胞凋亡的作用及其可能机制。方法 MTT法及集落形成实验检测氯尼达明对乳腺癌细胞MCF-7增殖的抑制作用；PI/Annexin-V双染检测细胞凋亡；ATP检测试剂盒检测细胞内ATP水平；Western blot检测葡萄糖调节蛋白78（GRP78）、凋亡抑制蛋白家族cIAP1及caspase-8蛋白的表达。结果 MTT结果显示，50~250 mmol · L-1氯尼达明可抑制MCF-7细胞的增殖活性，且呈浓度和时间依赖性。集落形成实验同样证明了上述结果。PI/Annexin-V双染结果表明，随着氯尼达明浓度的增加，MCF-7细胞的凋亡率也随之增加。50、150和250 mmol · L-1氯尼达明作用于MCF-7细胞5 h后，细胞内ATP水平与对照组相比分别为80.67%、62.78%和30.73%。Western blot检测发现，随着氯尼达明作用时间的延长， GRP78蛋白表达上调，cIAP1蛋白表达下调，同时增强了caspase-8的活性。结论氯尼达明可以抑制乳腺癌细胞MCF-7的增殖活性，诱导其产生凋亡，其机制可能与减少细胞内ATP的产生诱导内质网应激反应，并下调cIAP表达及增强caspase-8的活性有关。