槲皮素对肝癌HepG2细胞生长影响的体外研究

目的 观察槲皮素对肝癌HepG2细胞生长及hTERT基因表达的影响.方法 以台盼蓝拒染法计数肝癌细胞的生长抑制率,用透射电镜从形态变化方面了解凋亡的发生,流式细胞术检测细胞周期变化,Western-blot检测hTERT基因表达改变,PCR-TRAP法检测端粒酶活性.结果 槲皮素抑制肝癌HepG2细胞增殖的作用明显,且呈浓度和时间依赖性,槲皮素处理48 h后的半数抑药浓度（IC5o）为25.5μmol/L;形态学检测显示出了细胞凋亡的特征变化,经10-20 μm/L的槲皮素处理,肝癌HepG2细胞周期阻滞于G0/G1期,且HepG2细胞hTERT蛋白降低,端粒酶活性被抑制.结论 槲皮素能呈时间、剂量依赖性地抑制肝癌细胞的生长,能诱导HepG2细胞发生凋亡,其抑制增生与诱导凋亡的机制可能与下调hTERT基因表达、抑制端粒酶活性、破坏端粒稳定性有关.

Effects of Quercetin on Proliferation of Hepatocarcinoma Cell Line HepG2 in Vitro

Objective To investigate the effects of quercetin on the hepatocarcinoma cell line HepG2 and the expression of hTERT gene. Methods The number of viable cells was ascertained by trypan blue dye exclusion test. Morphological changes of apoptotic cells were observed by electronic microscopy. Cell cycle were analysed by flow cytometry. The telomerase activity was analysed by PCR- TRAP assay and hTERT gene expression was detected by RT- PCR and Western-blot. Results Quercetin had a significant inhibition to growth and proliferation of hepatocarcinoma cell line HepG2 by a concentration- dependent manner, The ICso was 25, 5 μmol/L after quercetin exposure for 48 h. Electron microscopy provided evidence that apoptosis occurred in the hepatoearcinoma cells of treated groups. FCM analyses showed that quercetin arrested HepG2 cells at the G0/G1 phase. The result of Western- blot showed that the expression of hTERT gene was significantly inhibited by quercetin and telomerase activity decreased. Conclusion Dose-dependent inhibitory effects of quercetin on the growth of hepatocarcinoma cell line HepG2 are remarkable. Quercetin could induce apoptosis of HepG2 cells. The down- regulating expression of hTERT gene, suppression of telomerase and destruction telomere may all contribute to the apoptosis mechanisms.