p73β基因转染对胃癌细胞的生物学影响

p73β Gene Transfection on the Biological Effects of Gastric Carcinoma Cells

目的研究人p73β基因转染对人胃癌细胞SGC-7901的生物学影响,探讨p73β基因抑制SGC-7901细胞增殖的机制。方法用脂质体转染法瞬时转染SGC-7901细胞,转染重组质粒pcDNA3.1-p73β(SGC-7901-pcDNA3.1-p73β组)和空载质粒pcDNA3.1-N0(SGC-7901-pcDNA3.1-N0组),并用未转染质粒具有相同遗传背景和代数的SGC-7901细胞作为空白对照(SGC-7901组)。逆转录-聚合酶链反应(RT-PCR)检测细胞中P73β、p21、c-myc表达量变化,MTT法观察细胞增殖的活力,原位细胞凋亡检测TUNEL法观察细胞凋亡。结果RT-PCR检测发现SGC-7901-pcDNA3.1-p73β组细胞与SGC-7901-pcDNA3.1-N0和SGC-7901两对照组相比,其p73β表达明显增高,p21相对表达量明显增多,c-myc相对表达量明显减少。与两对照组相比,SGC-7901-pcDNA3.1-p73β组细胞增殖率明显减弱,细胞凋亡率明显增高(均P<0.05)。结论p73β基因可以促进SGC-7901细胞内p21基因的表达,抑制c-myc基因表达。p73β基因可降低胃癌细胞增殖力,诱导胃癌细胞凋亡。

Objective To investigate the effect of wild-type p73β gene transfection on apoptosis of human gastric cancer cell line SGC-7901 and to explore the mechanism of p73β gene effect on inhibiting SGC-7901 cell proliferation.Methods The recombinant plasmid pcDNA3.1-N0 and empty plasmid pcDNA3.1-p73β were transfected into SGC-7901 cell line by LipofectAMINE 2000.The SGC-7901 Cell line that has the same genetic background and passage was used as the control.The expression of p73β,p21 and c-myc were detected by RT-PCR and the cell growth was detected by MTT.The apoptosis of the transfected SGC-7901 cells were examined by TUNEL method.Results The relative expressions of p73β and p21 in SGC-7901-pcDNA3.1-p73β cells were significantly higher than those in control group and SGC-7901-pcDNA3.1-N0 group.The relative expressions of c-myc in SGC-7901-pcDNA3.1-p73β cells were significantly lower than those in control group.Compared with the control group and SGC-7901-pcDNA3.1-N0 group,the cell proliferation was significantly decreased and the apoptosis rate was obviously increased in SGC-7901-pcDNA3.1-p73β group（all P0.05）.Conclusion p73β gene transfection up-regulated the expression of p21 and down-regulated the expression of c-myc in SGC-7901 cells,suggesting that p73β can inhibit the proliferation of SGC-7901 cells and induce apoptosis of gastric cancer cells.