融合型自杀基因系统Fcy：：Fur／5-FC对人肝癌细胞株HepG2体外杀伤作用的初步研究

A preliminary study of the role of fusion suicide gene system Fcy： Fur/5 -fluorocytosine in killing human hepatoma cell line HepG2 in vitro

目的研究融合型自杀基因Fcy：：Fur联合5-氟胞嘧啶（5-Fc）对人肝癌细胞株HepG2的杀伤作用。方法应用脂质体介导法将Fcy：：Fur基因转染人人肝癌细胞株HepG2，经G418筛选2周后行有限稀释法获得稳定表达Fcy：：Fur基因的单克隆细胞。5-Fc处理后，通过MTF法和AnnexinV—FITC＋PI双标记染色法，检测Fcy：：Fur／5～FC自杀基因系统对人肝癌细胞株HepG2的细胞增殖及凋亡的影响。结果MqT法检测显示稳定表达Fcy：：Fur基因的HepG2单克隆细胞经5-Fc处理后，在1、2、3、4、5天时对细胞的增殖有明显抑制作用。AnnexinV—FITC＋PI双标记染色法检测细胞凋亡率：1天为5．74％，2天为11．04％，3天为17．56％；PBS处理的细胞凋亡率：1天为3．67％，2天为3．68％，3天为4．42％，凋亡率无明显改变。结论Fcy：：Fur／5-FC自杀基因系统对人肝癌细胞株HepG2的增殖有明显的抑制作用，并可促进肿瘤细胞凋亡。

Objective To investigate the role of Fcy ：： Fur/5 - FC suicide gene system in killing human hepatocel- lular carcinoma HepG2 cells. Methods Fcy ：： Fur gene was transfected into HepG2 cells by LipofectamineTM 2000. 2 weeks after screening with G418, limiting dilution analysis was performed to obtain monoelonal cells of HepG2 clonical cells expressing Fcy ： Fur gene. Fcy ：＂ Fur gene was detected by reverse transcriptase - polymerase chain reaction （ RT - PCR） , followed by treatment with 5 -flurocytosine （5 -FC ） ,. and the detection of the proliferation and apoptosis of the monoclonal cells by MTT assay and Annexin V - FITC ＋ PI double labeling staining, respectively. Results MTT assay showed that HcpG2 monoclonal ceils expressing Fcy ＂： Fur gene, following 5 - FC treatment, had significant inhibitory effect on cell proliferation at 1 d, 2 d, 3 d, 4 d and 5 d. The apoptosis percentage of 5 - FC - treated cells by Annexin V-FITC ＋ PI double labeling staining： cells with was 5.74%, 11.04%, 17.56% at 1 d, 2 d, 3 d, respectively, which suggested cell apoptosis rate was positively correlated with the duration of drug administration. The percentage for the cells treated with PBS was 3.67% , 3.68% , 4.42% at 1 d, 2 d and 3 d, respectively, which showed no change in cell apoptosis rate. Conclusion Fcy ：： Fur/5 - FC suicide gene system can significantly inhibit the proliferation of HepG2 ceils and promote the apoptosis of cancer cells.