nm23-H1对全反式维甲酸诱导的人肝癌细胞凋亡及其相关信号转导通路的影响

为了解nm23-H1转染对全反式维甲酸诱导的人肝癌H7721细胞凋亡的影响,本研究通过质粒转染把nm23-H1导入人肝癌7721细胞,建立了nm23-H1过表达稳转细胞株。首先采用MTT法测定细胞生长曲线,再通过流式细胞术和丫啶橙染色法观察细胞凋亡,最后采用Western blot检测凋亡相关的信号通路分子bcl-2、PKB、PKB-Ser473、PKB-Thr308和p53的表达情况。研究发现,nm23-H1转染对人肝癌7721细胞的生长没有影响;但nm23-H1转染能明显促进全反式维甲酸诱导的细胞凋亡,nm23-H1转染细胞凋亡率为18.2%,而对照细胞凋亡率仅为1.0%;nm23-H1和对照细胞的过量表达对bcl-2的表达没有明显影响,但PKB的Ser473和Thr308位的磷酸化显著下调,抑癌基因p53的表达量上调。研究结果表明,nm23-H1的过量表达增加了人肝癌细胞对全反式维甲酸诱导的凋亡的敏感性,因此推测nm23-H1可作为肝癌治疗的有效靶点。

Effect of nm23-H1 on Cell Apoptosis and Relative Signal Transduction Path-way of Human Hepatocarcinoma Cells Induced by All Trans Retinoic Acid

To study the effect of nm23-H1 on the cell apoptosis induced by all trans retinoic acid (ATRA) and its signal transduction pathway. The plasmid with cDNA of nm23-H 1 was transfected into human H7721 hepatocarci-noma cell line, and the stable cell lines with expressions of nm23-H1 was established. Cell proliferation was detected by MTT method firstly, and then the cell apoptosis were observed by flow-cytometry and acridine orange staining. Finally, the expressions of signal transduction pathway molecule bcl-2,PKB,PKB-Ser473, PKB-Thr308 and p53 were examined using western blot. We found that nm23-H1 had no effect on cell proliferation of human H7721 hep-atoeareinoma cell line, but, the cells with overexpressed nm23-H 1 gene had significantly increased the ratio of all trans retinoic acid (ATRA) induced cell apoptosis, the ratio of apoptotic cells in nm23-H1 gene overexpressed cells was 18.2%, while that of the control cells only was 1.0%. On the other hand, the expressions ofbel-2 have no differ-ence in nm23-H1 and control cells overexpressed, but the phophorylation at T308 and S473 of PKB were obviously down regulated and the expressions of anti-oncogene p53 were up regulated. The result demonstrated that the over-expression of nm23-H1 increased the susceptibility of ATRA induced human H7721 hepatocarcinoma cell apopto-sis. Therefore, it suggests that nm23-H 1 gene might serve as an effective target for the treatment ofhepatocarcinoma.