珠子参体外诱导人肝癌细胞凋亡效应及机制研究

Panax japlcus var induced apoptosis of human hepatocarcinoma cells in vitro

目的观察珠子参体外诱导人肝癌细胞凋亡效应并初探其分子机制。方法体外细胞培养采用人肝癌细胞株SMMC-7721,分为对照(BL)组、珠子参(PJ)组、二甲基亚砜(DMSO)组及5-FU组,采用电镜观察作用后肝癌细胞超微结构改变;流式细胞仪检测肝癌细胞周期和凋亡率;RT-PCR法检测癌基因c-myc、c-fos和抑癌基因p53、p21表达的变化。结果与对照组比较,电镜下珠子参组SMMC-7721细胞染色质浓缩,分解成大小不一有膜包绕团块,内含有新月形DNA物质及细胞器,形成凋亡小体;周期分析可见G0/G1期细胞阻滞,阻止了细胞向S期的转换,并引起细胞凋亡,凋亡率达38.34%;RT-PCR半定量分析珠子参能降低癌基因c-myc表达(P<0.05),增高抑癌基因p53和p21表达(P<0.05)。结论珠子参能诱导人肝癌细胞SMMC-7721凋亡,部分作用机制可能与阻滞细胞停留在G0/G1,降低癌基因c-myc和c-fos表达,增高抑癌基因p53和p21表达有关。

Objective：To observe the effect of Panax japlcus var（PJ）on apoptosis of human hepatocarcinoma cell line SMMC-7721 in vitro and the molecular mechanism. Methods： Human hepatocarcinoma cell line SMMC-7721 were divided into 4 groups：control group, PJ group, DMSO group, and 5-FU group. The apoptotic morphologic changes of human hepatocarcinoma cells were observed by transmission electron microscope. Cell cycle and the apoptotic rate were detected by flow cytometry. The expressions of oncogenes c-myc and c-fos and anti-oncogenes p53 and p21 were determined by RT-PCR. Results：Compared with control group, PJ elicited typical apoptotic morphological changes identified by apoptotic body formation, chromatin condensation, mitochondria degeneration, and microvillus disappearance. Human hepatocarcinoma cells were accumulated at G0/G1 period while S period ratio fell （P〈0.05）. The apoptotic rate of PJ group was 38.34 %. The expressions of oncogenes c-myc and c-fos were reduced and the expressions of anti-oncogenes p53 and p21 were increased. Conclusions：PJ induced the apoptosis of human hepatocarcinoma cells SMMC-7721 which was partly due to G0/G1 arrest, down-regulation of c-myc and c-los expressions, and up-regulation of p53 and p21 expression.