谷氨酰胺酶反义基因诱导胃癌细胞凋亡的作用研究

Effects of GA antisense gene on apoptosis of gastric carcinoma cells

目的利用反义核酸技术封闭胃癌细胞的谷氨酰胺酶基因,观察反义GAcDNA能否对胃癌细胞的恶性表型有所逆转,为肿瘤的基因治疗探索一条新途径,也为后续研究及临床应用奠定基础。方法将含有GAcDNA片段的反义真核表达载体pcDNA3.0/GA,通过脂质体介导转入胃癌细胞SGC-7901,经筛选、鉴定,命名为SGC-7901GA,采用TUNEL法检测肿瘤细胞凋亡情况,观察反义核酸转染后胃癌细胞凋亡的改变。结果pcDNA3.0/GA通过脂质体介导转染胃癌细胞SGC-7901,PCR证实GAcDNA目的片段已经整合到了SGC-7901细胞基因组,获得的G418抗性细胞命名为SGC-7901GA。检测胃癌细胞的凋亡情况表明重组质粒转染后SGC-7901GA的TUNEL阳性细胞数量显著上升,与对照组比较差异有统计学意义。结论本实验通过含有GAcDNA片段的反义真核表达载体pcDNA3.0/GA转染胃癌细胞株,发现胃癌细胞的凋亡指数增加,提示肿瘤细胞恶性程度有所降低,反义核酸技术封闭谷氨酰胺酶基因可能成为肿瘤基因治疗的一条新途径。

Objectives To study whether antisense GAcDNA can inverse malignancy phenotype of the gastric carcinoma cells by blocking the glutaminase gene with antisense nucleotide techniques in order to explore a new approach for the gene therapy of tumor and to establish the foundation of following research and clinical application. Methods We transfected the antisense eukaryotic ex pression vector contenting the segment of GAcDNA into gastric carcinoma cells （SGC-7901） by liposomes. This transfected cells were named SGC-7901^GA after filtration and identification. We compared the differences of apoptosis with terminal deoxynucleotidyl transferase-mediated nick end labeling technique （TUNEL） between transfected cells and untransfected cells. Results Through transfection by liposomes,GAcDNA segment was integrated into the genome of SGC-7901 cells,which was confirmed by PCR. The transfected cells, which can live after selecting with G418, were named SGC-7901^GA. The apoptosis index of SGC-7901^GA was significant higher than that of control group（P〈0.01）. Conclusion Through transfecting antisense eukaryotic expression vector contenting the segment of GAcDNA into gastric carcinoma cells, we find the apoptosis index is increased and the level of tumor＇s malignancy is decreased. Blocking the gene of glutaminase with antisense nucleotide techniques may be a new way for the gene therapy of tumor.