【摘要】 目的探讨慢病毒介导胞嘧啶脱氨酶(CD)和胸苷激酶(TK)融合双自杀基因系统对胃癌细胞SGC-7901的杀伤作用。方法用重组慢病毒FGW-KDRP-CD/TK体外感染胃癌SGC-7901细胞,荧光显微镜观察其感染效率,Giemsa染色法观察转基因的胃癌细胞形态学变化;用流式细胞术观察细胞周期的变化。RT-PCR法检测受感染细胞CD/TK基因的表达。然后加用前药更昔洛韦(GCV)和/或5-氟胞嘧啶(5-FC)用MTT法检测该体系对胃癌细胞的杀伤作用。结果慢病毒的感染率随病毒滴度的增高而递增。Giemsa染色法显示慢病毒载体对体外培养的胃癌细胞形态无明显影响。流式细胞仪检测慢病毒感染胃癌细胞前后,处于G0-G1,G2-M,S期的细胞百分比差异无统计学意义(P>0.05)。经RT-PCR检测发现转基因细胞有目的基因的表达。MTT法检测显示前药GCV和5-FC在一定浓度搭配范围内呈剂量依赖性地抑制SGC-7901细胞增殖,未转染慢病毒的细胞对前药不敏感;联合两种前药对SGC-7901的疗效优于任一单用前药(P<0.05)。联合用药[(0.1+40)、(1+80)、(10+160)、(100+320)]mg/L具有协同作用(CDI均<1)。结论慢病毒能介导CD/TK双自杀基因体系靶向杀伤胃癌细胞,联合用药有协同作用。更多还原

【Abstract】 Objective To study the selective cytotoxic effect of lentivirus-mediated double suicide gene (CD/TK) against human gastric carcinoma cells SGC-7901 in vitro. Methods SGC-7901 cells were infected with FGW-KDRP-CD/TK vector and the infection efficiency was observed under a fluorescence microscope. The morphological changes of the infected cells were observed by Giemsa staining. Flow cytometry (FCM) was employed for cell cycle analysis, and the expression of CD/TK was detected by RT-PCR. The infected cells were then treated with the prodrugs ganciclovir (GCV) and/or 5-fluorocytosine (5-FC) at different concentrations, and the cytotoxic effects were evaluated using MTT method. Results The infection efficiency of the lentiviral vector in SGC-7901 cells increased with the titer of the virus, which produced no significant effect on the cancer cell morphology in vitro or on the percentages of G0-G1, G2-M and S phase cells (P>0.05). RT-PCR demonstrated the expression of CD/TK gene in SGC-7901 cells infected by FGW-KDRP-CD/TK. The infected cells were highly sensitive to the prodrugs with a dose-dependent cytotoxic effect within a specific concentration range of the drugs, whereas the non-infected cells were not sensitive to the prodrugs. Combined use of the two prodrugs produced an obviously stronger inhibitory effect than either of the them (P<0.05). When combined, GCV and 5-FC at the concentration of 0.1+40, 1+80, 10+160, and 100+320 mg/L demonstrated a synergetic effect with a CDI<1. Conclusion Lentivirus-mediated CD/TK fusion gene system can selectively kill gastric cancer cells, and the two prodrugs show a synergistic cytotoxic effect.更多还原