姜黄素调节PI3K/AKT/mTOR信号通路对胃癌细胞增殖、凋亡和化疗耐药性的影响

Effect of curcumin on proliferation,apoptosis,and chemotherapy resistance of gastric cancer cells by regulating the PI3K/AKT/mTOR signaling pathway

[目的]探讨姜黄素(Cur)调节磷脂酰肌醇3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/AKT/mTOR)信号通路对胃癌细胞增殖、凋亡和化疗耐药性的影响。[方法]将MGC-803细胞分为对照组、Cur低剂量组、Cur中剂量组、Cur高剂量组、Cur高剂量+740Y-P组,用于MGC-803细胞增殖、凋亡行为的检测。将MGC-803/DDP细胞分为空白组、Cur组、顺铂(DDP)组、Cur+DDP组、Cur+DDP+740Y-P组,用于MGC-803/DDP细胞化疗耐药性的检测。克隆形成实验、CCK-8检测MGC-803或MGC-803/DDP细胞增殖;流式细胞术检测MGC-803或MGC-803/DDP细胞凋亡;Western blot检测细胞中抗增殖细胞核抗原(PCNA)、Bcl2关联X蛋白(Bax)、多药耐药关联蛋白1(MRP1)、p-PI3K、p-AKT、p-mTOR蛋白表达。[结果]与对照组比较,Cur低剂量组、Cur中剂量组、Cur高剂量组MGC-803细胞增殖能力、克隆形成率及PCNA、p-PI3K、p-AKT、p-mTOR蛋白表达降低,细胞凋亡率及Bax蛋白表达升高,且呈剂量依赖性(P<0.05),表明Cur可抑制PI3K/AKT/mTOR通路及MGC-803细胞增殖,并诱导细胞凋亡;与Cur高剂量组比较,Cur高剂量+740Y-P组MGC-803细胞活性、克隆形成率及PCNA、p-PI3K、p-AKT、p-mTOR蛋白表达升高,细胞凋亡率及Bax蛋白表达降低(P<0.05),表明Cur可能通过抑制PI3K/AKT/mTOR通路抑制MGC-803细胞增殖,诱导细胞凋亡。与空白组比较,Cur组、DDP组MGC-803/DDP细胞增殖能力、克隆形成率及MRP1、p-PI3K、p-AKT、p-mTOR蛋白表达降低,凋亡率升高(P<0.05),表明MGC-803/DDP细胞的耐药性及PI3K/AKT/mTOR通路的激活程度高于MGC-803细胞;与Cur组、DDP组比较,Cur+DDP组MGC-803/DDP细胞增殖能力、克隆形成率及MRP1、p-PI3K、p-AKT、p-mTOR蛋白表达降低,凋亡率升高(P<0.05),表明Cur可抑制PI3K/AKT/mTOR通路并降低MGC-803/DDP细胞耐药性;与Cur+DDP组比较,Cur+DDP+740Y-P组MGC-803/DDP细胞增殖能力、克隆形成率及MRP1、p-PI3K、p-AKT、p-mTOR蛋白表达升高,凋亡率降低(P<0.05),表明Cur可能通过抑制PI3K/AKT/mTOR通路降低MGC-803/DDP细胞耐药性。[结论]Cur抑制MGC-803细胞增殖,促进细胞凋亡并降低DDP耐药性的机制可能与抑制PI3K/AKT/mTOR通路有关。

[Objective]To investigate the effect of curcumin(Cur)on the proliferation,apoptosis,and chemotherapy resistance of gastric cancer cells by regulating the phosphatidylinositol 3 kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)signaling pathway.[Methods]MGC-803 cells were separated into control group,Cur low-dose group,Cur medium dose group,Cur high-dose group,and Cur high-dose+740Y-P group for the detection of MGC-803 cell proliferation and apoptosis behavior.MGC-803/DDP cells were separated into blank group,Cur group,cisplatin(DDP)group,Cur+DDP group,and Cur+DDP+740Y-P group for the detection of chemotherapy resistance in MGC-803/DDP cells.Cloning experiments and CCK-8 were applied to detect MGC-803 or MGC-803/DDP cell proliferation;flow cytometry was applied to detect apoptosis of MGC-803 or MGC-803/DDP cells;Western blot was applied to detect the expression of anti-proliferating cell nuclear antigen(PCNA),Bcl2 associated X protein(Bax),multidrug resistance associated protein 1(MRP1),p-PI3K,p-AKT,and p-mTOR proteins in cells.[Results]Compared with the control group,the colony formation rate,proliferative ability,and expression of PCNA,p-PI3K,p-AKT,and p-mTOR proteins in MGC-803 cells reduced in the Cur low-dose group,Cur medium dose group,and Cur high-dose group,the apoptosis rate and the expression of Bax protein increased,in a dose-dependent manner(P<0.05),the results indicated that Cur could inhibit PI3K/AKT/mTOR pathway and MGC-803 cell proliferation,and induce cell apoptosis;compared with the Cur high-dose group,the colony formation rate,proliferative ability,and expression of PCNA,p-PI3K,p-AKT,and p-mTOR proteins in MGC-803 cells increased in the Cur high-dose+740Y-P group,the apoptosis rate and expression of Bax protein decreased(P<0.05),these results indicated that Cur could inhibit the proliferation of MGC-803 cells and induce apoptosis by inhibiting PI3K/AKT/mTOR pathway.Compared with the blank group,the colony formation rate,proliferative ability,and expression of PCNA,p-PI3K,p-AKT,and p-mTOR proteins in MGC-803 cells in the Cur and DDP groups reduced,the apoptosis rate increased(P<0.05),the results showed that MGC-803/DDP cells had higher drug resistance and PI3K/AKT/mTOR pathway activation than MGC-803 cells;compared with the Cur and DDP groups,the colony formation rate,proliferative ability,and expression of PCNA,p-PI3K,p-AKT,and p-mTOR proteins in MGC-803 cells in the Cur+DDP group decreased,the apoptosis rate increased(P<0.05),the results indicated that Cur could inhibit PI3K/AKT/mTOR pathway and reduce drug resistance of MGC-803/DDP cells;compared with the Cur+DDP group,the colony formation rate,proliferative ability,and expression of PCNA,p-PI3K,p-AKT,and p-mTOR proteins in MGC-803 cells in the Cur+DDP+740Y-P group increased,the apoptosis rate decreased(P<0.05),these results indicated that Cur might decrease the drug resistance of MGC-803/DDP cells by inhibiting PI3K/AKT/mTOR pathway.[Conclusion]The mechanism of Cur inhibiting MGC-803 cell proliferation,promoting cell apoptosis and reducing DDP resistance may be related to inhibition of PI3K/AKT/mTOR pathway.