新型化合物1通过PI3K/AKT/mTOR信号通路抑制三阴性乳腺癌MDA-MB-231细胞的存活

摘要

Objective Compound 1 is a compound with novel structure,which is isolated form secondary metabolites of penicillium oxalicum.This study aimed to examine the mechanisms of Compound 1 inhibiting the viability of three negative breast cancer MDA-MB-231 cells with the PI3K/Akt/mTOR signaling pathway focused on.Methods The cytotoxic effect of Compound 1 on breast cancer cells MDA-MB-231 and normal rat myocardial cells H9C2 were evaluated by MTT assay.The distribution of cell cycle was assessed by flow cytometry and Western blotting.Western blotting was performed to detect the effect of Compound 1 on the PI3K/AKT/mTOR signaling pathway.Results Compound 1 could inhibit the viability of MDA-MB-231 cells in a time-and concentration-dependent fashion.Moreover,Compound 1 was found to lead to a decrease in protein p53,cyclinB1,cyclinD1 and an increase in p21,and it could induce cell arrest in G2/M phase.The further studies revealed that Compound 1 could down-regulate not only the PI3K/AKT/mTOR signaling pathway in MDA-MB-231 cells but also the hyper-activated mTOR pathway in PTEN-/-mouse embryonic fibroblast(MEF)cells.Conclusion The mechanism of Compound 1 selectively inhibiting the viability of MDA-MB-231 cells may involve the down-regulation of PI3K/Akt/mTOR.Compound 1 is expected to become an effective natural compound for the treatment of cancers with the mTOR pathway abnormally activated.%目的 探讨从草酸青霉菌的次级代谢产物分离出来的化合物1抑制三阴性乳腺癌细胞MDA-MB-231存活的相关机制.方法 MTT法检测化合物1对MDA-MB-231细胞和正常大鼠心肌细胞H9C2存活率的影响.通过流式细胞术和Western blot检测细胞周期分布,通过Western blot方法进一步研究化合物1对PI3K/AKT/mTOR信号通路的影响.结果 化合物1呈时间和浓度依赖的方式抑制MDA-MB-231细胞的存活率.化合物1可使MDA-MB-231细胞p53、CyclinB1、CyclinD1蛋白表达减少,p21蛋白增加,并阻滞乳腺癌细胞在G2/M期.进一步发现化合物1不仅能够抑制MDA-MB-231细胞中被血清激活的PI3K/AKT/mTOR信号通路,还能作用于PTEN缺失的小鼠胚胎成纤维细胞(MEF),抑制其过度活化的mTOR通路.结论 化合物1选择性抑制MDA-MB-231细胞存活的机制可能与它能够抑制异常活化的PI3K/AKT/mTOR信号通路有关.化合物1可望成为一种潜在的治疗AKT/mTOR信号通路异常活化肿瘤的天然化合物.