人参皂甙Rh2对食管癌Eca-109细胞caspase3、caspase8基因的影响

Ginsenoside Rh2 up-regulates caspase 3 and caspase 8 expression in human esophageal cancer cell line Eca-109

目的:探讨人参皂甙Rh2诱导人食管癌Eca-109细胞凋亡过程中caspase3、caspase8凋亡调节基因的相互关系及可能的作用机制.方法:应用MTT法测定其对细胞的生长抑制作用,流式细胞术分析人参皂甙Rh2作用后细胞凋亡及增殖的变化,应用免疫细胞化学及Western blot技术检测用药前后凋亡相关基因caspase3、caspase8蛋白表达的变化.结果:人参皂甙Rh2对人食管癌Eca-109细胞有生长抑制作用,并呈时效和量效依赖关系.流式细胞仪分析结果发现,食管癌Eca-109细胞在DNA组方图上出现典型的亚二倍体峰即凋亡峰,在细胞周期中的分布也发生了明显的变化,其48h凋亡率明显高于对照组(19.10%±2.12% vs 2.10%±0.87%,P<0.01).免疫细胞化学及Western blot技术结果显示,20mg/L人参皂甙Rh2作用72h后食管癌Eca-109细胞caspase3、caspase8蛋白表达明显升高(0.35±0.04 vs 0.10±0.02,0.84±0.06 vs 0.31±0.11,均P<0.05).结论:人参皂甙Rh2具有诱导食管癌Eca-109细胞凋亡和抑制细胞分化的作用,其分子机制可能是上调caspase3、caspase8蛋白表达.

AIM：To investigate the effect of ginsenoside Rh2 on the expression of caspase 3 and caspase 8 in human esophageal cancer cell line Eca-109 to explore possible mechanisms underlying the apoptosis-inducing activity of ginsenoside Rh2.METHODS：After Eca-109 cells were treated with ginsenoside Rh2,cell growth was detected by MTT assay;cell apoptosis was determined by flow cytometry;and the expression of apoptosisassociated proteins caspase 3 and caspase 8 was measured by immunocytochemistry and Western blot.RESULTS：Ginsenoside-Rh2 inhibited the growth of Eca-109 cells in a dose-and time-dependent manner.Apoptotic cells were observed on a DNA histogram as a subdiploid or pre-G1 peak.Treatment with ginsenoside Rh2 significantly altered cell cycle distribution,and the apoptosis rate of cells treated with ginsenoside Rh2 was signif icantly higher than that of control cells（19.10% ± 2.12% vs 2.10% ± 0.87%,P 〈0.01）.Compared with control cells,the expression of caspase 3 and caspase 8 proteins was up-regulated significantly in Eca-109 cells treated with 20 mg/L ginsenoside Rh2 for 72 h（0.35 ± 0.04 vs 0.10 ± 0.02,0.84 ± 0.06 vs 0.31 ± 0.11,both P 〈0.05）.CONCLUSION：Ginsenoside Rh2 induces the apoptosis of Eca-109 cells possibly by up-regulating the expression of caspase 3 and caspase 8.