腺病毒载体介导的早幼粒细胞白血病基因生长抑制因子诱导胃癌细胞凋亡的机制研究

目的 探讨腺病毒载体介导的早幼粒细胞白血病基因（PML）生长抑制因子诱导胃癌细胞凋亡作用的机制。方法 将人PML全长cDNA插入穿梭质粒pSGCMV，再与腺病毒骨架质粒pPE3共转染293细胞后获得重组病毒。用重组病毒感染胃癌细胞系SGC-7901，采用噻唑蓝比色法、流式细胞术以及免疫细胞化学法对p53和bcl-2在肿瘤细胞内的表达以及细胞凋亡的定性与定量指标进行检测。结果 经腺病毒介导的PML处理的SGC-7901细胞生长受到明显抑制，凋亡细胞发生率升高，且与MOI值呈正相关，MOI值由5增加到20，细胞的生长抑制率从22．4％增加到38．5％，而细胞凋亡率从37．2％增加到49．8％。经腺病毒介导的PML处理的SGC-7901细胞内p53蛋白表达较对照组明显增加，bel-2蛋白的表达则无明显变化。结论 腺病毒介导的PML对胃癌细胞的杀伤主要是通过诱导细胞凋亡，p53蛋白高表达为其诱发胃癌细胞凋亡的机制之一。

Adenovirus mediated PML growth suppressor induces apoptosis of gastric cancer cells

Objective To investigate the apoptosis induced by adenovirus mediated PML growth suppressor in SGC-7901 gastric cancer ceils. Methods Human full-length PML cDNA was cloned into shuttle plasmid pSGCMV, the constructed plasmid containing PML gene was co-transfected into 293 cells together with backbone plasmid pPE3 to obtain recombinant adenovirus Ad-pml. Ad-pml was used to infect SGC-7901 cells. The expression of p53 and bcl-2 in SGC-7901 cells and qualitative, quantitative index of cell apoptosis were detected with MTT, flow cytometry and immunohistochemical method. Results The growth of SGC-7901 cells was inhibited and the apoptosis rate was increased by adenovirus mediated PML in a MOI- dependent manner. The expression of p53 protein was increased and that of bcl-2 protein was unchanged in SGC-7901 cells after treated with adenovirus mediated PML. Conclusions Adenovirus mediated PML exerts its cytotoxic effect on SGC-7901 ceils by inducing apoptosis. The increase of p53 protein expression is the mechanism inducing gastric cancer cell apoptosis.