葫芦素B抑制人顺铂耐药胃癌细胞的作用及机制研究

Inhibitory Effect of Cucurbitacin B on Human Cisplatin Resistant Gastric Cancer Cells and Related Mechanism

目的:探讨天然化合物葫芦素B(Cucurbitacin B,Cu B)在顺铂(Cisplatin,DDP)耐药的人胃癌细胞(Gastric cancer,GC)中的作用及作用机制。方法:通过MTT法和软琼脂集落形成实验测定Cu B对DDP耐药的人胃癌细胞系SGC7901/DDP的毒性作用;Western blot法检测Cu B对耐药相关因子的表达水平的影响;激光共聚焦显微镜检测自噬、DAPI染色检测凋亡;Western blot和PP2A活性检测探讨Cu B在SGC7901/DDP中的作用机理。结果:Cu B能够抑制SGC7901/DDP细胞的生长,诱导自噬、凋亡及逆转DDP耐药。并且能够抑制与肿瘤多药耐药相关蛋白的表达,包括P-糖蛋白(P-glycoprotein,P-gp)和多药耐药性相关蛋白(multidrug resistance-associated protein 1,MRP1),抑制CIP2A/PP2A/m TORC1信号通路活化。结论:Cu B能够抑制SGC7901/DDP细胞增殖并且通过抑制CIP2A/PP2A/m TORC1信号通路诱导细胞自噬和凋亡,可以作为治疗DDP耐药的新的有效药物进行研究。

Objective To investigate the antitumor effects and possible mechanisms of the natural compound of Cucurbitacin B（ Cu B） on cisplatin（ DDP） resistant human gastric cancer（ GC） cells（ SGC7901/DDP）. Methods MTT and colony formation assay were used to detect the cytotoxic effects of Cu B on SGC7901/DDP cells. The expression levels of multidrug resistance（ MDR） related-factors were detected by Western blot analysis. Laser confocal microscopy and DAPI staining were used to detect autophagy and apoptosis respectively. The expression of CIP2 A/PP2 A/m TORC1 pathway proteins was determined by Western blot analysis and PP2 A activity assay. Results Cu B could inhibit the growth of SGC7901/DDP cells. The expression of MDR-related factors were down-regulated by Cu B. Including P-glycoprotein（ P-gp） and multidrug resistance-associated protein 1（ MRP1）,thereby inhibiting the activity of CIP2 A/PP2 A/m TORC1 signaling pathway.Conclusion Cu B can inhibit cell proliferation of SGC7901/DDP and induce autophagy and apoptosis through the inhibition of CIP2 A/PP2 A/m TORC1 signaling pathway. It can be used as a new effective candidate for the treatment of DDP resistant gastric cancer and related investigation.