莪术醇抑制人肝癌细胞HepG2增殖的机制

目的:探讨莪术醇在体外对人肝癌HepG2细胞的增殖和细胞周期的影响及其分子机制.方法:体外培养HepG2细胞,采用四甲基偶氮唑蓝(MTT)比色法观察莪术醇对HepG2细胞增殖的抑制作用,流式细胞术分析莪术醇处理后HepG2细胞的周期分布,TaqMan探针实时荧光定量PCR法及Western印迹检测细胞周期调控相关基因的表达水平.结果:莪术醇对HepG2细胞的增殖具有明显抑制作用,且在一定范围内(2.5～10mg·L-1)呈浓度和时间依赖性；莪术醇诱导HepG2细胞发生G1期阻滞,伴随cyclin D1,CDK2,CDK8,pRB1,p27KIPl mRNA表达水平增高,而cyclin A1的水平则下调,cyclin E1和CDK4的表达不受影响,p53及其下游调控蛋白p21WAF1和Wip1表达水平增高.结论:莪术醇诱导人肝癌HepG2细胞G1期阻滞、抑制细胞增殖,其作用可能通过激活p53与pRB通路,抑制cyclin A1基因的表达和上调p21 WAF1,p27KIP1以及CDK8基因的表达而实现的.

Mechanism study on anti-proliferative effects of curcumol in human hepatocarcinoma HepG2 cells

Objective: To investigate the anti-proliferative effects of curcumol, an herbal extract from curcuma, in human hepatocarcinoma HepG2 cells, and its possible molecular mechanism. Method: The effects of curcumol on human hepatocarcinoma cells were assessed in vitro. Proliferation of HepG2 cells treated with various concentration(2.5-10 mg·L^-1)of curcumol was determined using the MTT assay and the distribution of cell cycle of HepG2 cells was analyzed using the FCM technique. Expression of 14 cell cycle regulation-related genes were assessed by TaqMan real-time polymerase chain reaction (RT-PCR) method and Western blot. Result: Curcumol significantly inhibited the proliferation of HepG2 cells and induced G₁ phase arrest in a dose- and time-dependent manner. The mRNA levels of pRB1, cyclin D1, CDK2, CDK8 and p27KIP1 were elevated, while cyclin A1 decreased, in both of the low (25 mg·L^-1) and the high dose (100 mg·L^-1) treatment of curcumol. There were no significant changes in the expression of either cyclin E1 or CDK4. The expression of p53 and its target genes p21WAF1 and Wip1 protein were increased. Conclusion: Curcumol can inhibit the proliferation of HepG2 cells in vitro and induce G₁ arrest of cell cycle through mechanisms activating p53 and pRB pathways that involve genes of cyclin A1, CDK2, CDK8, p21WAF1 and p27KIP1.