论文部分内容阅读
目的:通过检测IFN-γ基因转染对大肠癌细胞表面抗原的表达情况、对细胞的生长抑制、细胞周期的影响情况,初步探讨IFN-γ基因治疗抗肿瘤作用的机制.方法:制备含人IFN-γ基因的真核表达质粒pcDNA-3-IFN-γ,利用阳离子脂质体将其转染进入人大肠癌细胞株LOVO、SW62O、HCT116BG及人宫颈癌细胞株Hela,检测基因转染后IFN-γ基因的表达情况,同时检测基因转染对大肠癌细胞CEA、HLA-DR抗原表达的诱导作用和细胞凋亡及细胞周期的变化.结果:基因转染后,原来高表达CEA的细胞株(LOVO、HCT116BG)其上清中CEA含量增加明显(从21.25±6.76μ/l增加到34.96±7.07μg/lP<0.05),而原来低表达甚至不表达CEA的细胞株(Hela、SW620)其上清CEA含量则无明显增加(P>0.05).各细胞株表面的HLA-DR的表达量在导入IFN-γ基因后明显增强(平均表达率从3.91±3.61%增加到11.67±7.20%P<0.01).通过对细胞的凋亡情况和细胞周期的变化显示:转染IFN-γ基因后促进了LOVO细胞的凋亡(各时段平均凋亡率对照组与治疗组分别为8.27±5.62%与15.32±11.41%P<0.05),细胞的S期比例随作用时间延长而呈逐渐降低趋势,显示了基因转染后DNA的合成代谢受到抑制.结论:IFN-γ基因转染后可有效增强大肠癌细胞表面抗原的表达,诱导机体产生抗肿瘤免疫应答;并可能通过抑制细胞DNA的合成,促进细胞的凋亡,抑制肿瘤细胞的增生等机制发挥抗肿瘤作用.
OBJECTIVE: To investigate the mechanism of anti-tumor effect of IFN-γ gene therapy by detecting the expression of surface antigens of colorectal cancer cells by IFN-γ gene transfection on the growth inhibition and cell cycle of human colorectal cancer cells.Methods: IFN-γ gene eukaryotic expression plasmid pcDNA-3-IFN-γ, which was transfected into human colorectal cancer cell lines LOVO, SW62O, HCT116BG and human cervical cancer cell line Hela by cationic liposome, IFN-γ gene expression, and detect gene transfection of colorectal cancer cells CEA, HLA-DR antigen expression induction and apoptosis and cell cycle changes.Results: After gene transfection, the original high expression of CEA cells (LOVO, HCT116BG), the CEA content in the supernatant increased significantly (from 21.25 ± 6.76μ / l to 34.96 ± 7.07μg / lP <0.05), while the original cell line (Hela, SW620) (P> 0.05). The expression of HLA-DR on the surface of each cell line was significantly increased after the introduction of IFN-γ gene (average expression rate increased from 3.91 ± 3.61% to 11.67 ± 7.20% P <0.01). Through the cell apoptosis and cell cycle changes significantly The results showed that the apoptosis of LOVO cells was promoted after IFN-γ gene transfection (average apoptotic rate was 8.27 ± 5.62% and 15.32 ± 11.41% P <0.05 respectively in each time period), and the proportion of cells in S phase The results showed that the synthesis of DNA was inhibited after transfection.Conclusion: Transfection of IFN-γ gene can effectively enhance the expression of surface antigens in colorectal cancer cells and induce the anti-tumor immune response in vivo. And may play an antitumor effect by inhibiting the synthesis of DNA, promoting cell apoptosis and inhibiting the proliferation of tumor cells.