过氧化物酶体增殖物激活受体γ激动剂对增强人结肠癌化疗敏感性的作用

Effect of rosiglitazone,a peroxisome proliferator-activated receptor γ (PPARγ) agonist,in sensitizing 5-fluorouracil chemotherapy for colon cancer

目的探讨过氧化物酶体增殖物激活受体γ(PPARγ)激动剂罗格列酮对人结肠癌LOVO细胞化疗敏感性的影响。方法体内实验:建立人结肠癌LOVO细胞裸鼠移植瘤模型,应用罗格列酮、5-Fu及两药联用连续灌胃给药两周,每2天测量瘤体的最长径和最短径,计算肿瘤体积和抑制率;体外实验:采用MTT法检测罗格列酮、5-Fu及两药联用对LOVO细胞生长的抑制作用,Hoechst染色检测细胞核形态,碘化丙啶(PI)染色流式细胞术检测细胞周期分布,Western blotting法检测Cyclin A1、Cyclin E1和Cdk2蛋白的表达变化。结果体内实验:罗格列酮、5-Fu及其联合用药组对裸鼠移植瘤抑制率分别为67.97%、74.9%和80.49%,两药联合为相加作用;体外实验:罗格列酮能够增强5-Fu对细胞的生长抑制作用,并呈现剂量和时间依赖性;细胞周期检测显示,5-Fu联合罗格列酮使S期细胞增多;与对照组相比,5-Fu处理组及联合用药组Cyclin A1表达量下调显著(P<0.01),与5-Fu组相比,联合用药组Cyclin A1表达量下调显著(P<0.01);与对照组相比,实验各用药组Cyclin E1、Cdk2表达量均下调显著(P<0.01),与5-Fu组相比,联合用药组Cyclin E1表达量下调显著。结论罗格列酮能够增强5-Fu的化疗效果,其机制与其诱导细胞凋亡及S期细胞周期阻滞有关。

Objective To explore rosiglitazone-induced sensitization of LOVO cells to 5-Fu.Methods In vivo studies： a heterotopic xenograft model in athymic mice using LOVO human colon cancer cell was established,and the animals were treated with rosiglitazone and/or 5-Fu through intragastric administration for two weeks.Tumors were measured for length and width every other day,and tumor volumes and inhibition rates were calculated.In vitro studies： the anti-proliferation effect of rosiglitazone in conjunction with 5-Fu to LOVO cells was measured using the MTT assay.The morphology of nuclei was observed after staining with Hoechst 33342.Cell cycle distribution was detected using flow cytometry after propidium iodide staining.Expression of Cyclin A1,Cyclin E1 and Cdk2 was detected by Western blotting analysis.Results In vivo studies： the tumor inhibition rates of rosiglitazone,5-Fu,and rosiglitazone plus 5-Fu were 67.97%,74.9% and 80.49%,respectively.The two drugs were found to have an additive effect.In vitro studies： rosiglitazone sensitizes 5-Fu′s growth inhibition to LOVO cells in a dose-and time-dependent manner.Cell numbers of S phase were increased by 10 μmol/L 5-Fu plus rosiglitazone.The 5-Fu group showed Cyclin A1 down-regulation relative to the control group,and the 5-Fu/rosiglitazone group showed further Cyclin A1 down-regulation.Compared to the control group,all the drug groups exhibited down-regulation of Cyclin E1 and Cdk2,and the 5-Fu/rosiglitazone group exhibited further Cyclin E1 down-regulation.Conclusion Rosiglitazone enhances 5-Fu-induced LOVO cell growth inhibition through S cycle arrest.