Ciglitazone抑制人肝癌HepG2细胞增殖活性的实验研究

Influence of Ciglitazone on hepatic cancer cells HepG2 growth in vitro and in vivo and its mechanisms

目的 研究过氧化物酶体增殖物激活受体γ(PPARγ)激动剂Ciglitazone对人肝癌细胞株HepG2体内、外生长的影响。并探讨其可能机制。方法 培养HepG2细胞,加入不同浓度的Ciglitazone,用生长曲线检测HepG2细胞体外生长情况,用流式细胞仪进行细胞周期分析;Western blot检测Ciglitazone对PPARγ蛋白表达的影响。建立裸鼠肝癌动物模型,随机将其分为两组:对照组(A组,10只),Ciglitazone注射组(B组,10只),B组隔天注射Ciglitazone 100 μl(100μmol/L)连续15次,对照组注射100μl生理盐水,1个月后,切除瘤灶、称瘤重、计算抑瘤率。标本用Western blot检测细胞周期素D1(CyclinD1)、细胞周期素依赖性激酶抑制子p21蛋白的表达。结果 (1)Ciglitazone体外抑制HepG2细胞生长,并呈现明显时间和剂量依赖性。(2)经Ciglitazone处理后PPARγ蛋白表达增加。(3)经Ciglitazone治疗后,A组、B组的瘤重分别为(3.73±0.22)g、(2.60±0.35)g,抑瘤率达30％,A组的CyclinD1较B组明显增高,A组的p21蛋白表达水平较B组明显降低。结论 Ciglitazone能抑制肝癌HepG2细胞的恶性增殖(呈明显的时间及剂量依赖性),并诱导其分化,其机制与PPARγ干预细胞周期的调控有关。

Objective To study the effect of the Ciglitazone on hepatic cancer cells HepG2 growth in vitro and in vivo and its mechanisms. Methods HepG2 cells were cultured in the presence of Ciglitazone at different concentrations. The in vitro growth of HepG2 cells was assessed by a growth curve. The cell cycle was analyzed by flow cytometry. The effect of Ciglitazone on the expression of PPARγ was detected by using Western blot. HepG2 cells (1 × 10~6/mouse) were inoculated subcutaneously into 20 nude mice, which were randomly divided into two groups: the control group (group A, n = 10) and the Ciglitazone treated group (group B, n = 10). The weights of subcutaneous tumor were measured. The expression of CyclinD1 and p21 was analyzed by Western blot. Results The proliferation of HepG2 was inhibited by Ciglitazone in a dose- and time- manner. There were more cells arrested in G_1/G_0 phase and the expression of PPARγ was markedly up-regulated in HepG2 cells treated with Ciglitazone. And more importantly, the direct injection of Ciglitazone into HepG2-induced tumors could suppress hepatic cancer growth in nude mice with the tumor growth inhibitory rate being 30 %. The expression of CyclinD1 in group A was increased significantly as compared with that in group B. The level of p21 was decreased significandy in group A as compared with that in group B. Conclusion Ciglitazone could significantly inhibit HepG2 proliferation dose-dependently and time-dependently, and its mechanism may be due to the fact that it can induce the differentiation of HepG2.