甲胎蛋白特异启动元件介导的肝癌靶向性基因治疗的体外实验研究

Experimental Studies in vitro on the α Fetoprotein specific Promoter Mediated Target Gene Therapy of Hepatocellular Carcinoma

目的采用体外培养的肿瘤细胞系探讨甲胎蛋白特异启动元件介导的靶向性肝癌基因治疗。方法将２．２ｋｂ的重组人甲胎蛋白（ＡＦＰ）基因顺式调控元件克隆于胞嘧啶脱氨酶（ＣＤ）基因的上游，构建逆转录病毒载体ＬＸ２．２ＣＤ。再以此载体和另一不含ＡＦＰ基因调控元件的逆转录病毒载体ｐＣＤ２分别转染３种肝癌细胞系和１种肺腺癌细胞系，筛选出整合ＣＤ基因的抗Ｇ４１８克隆，并进行细胞生长抑制实验。结果５氟胞嘧啶（５ＦＣ）对用ＬＸ２．２ＣＤ转染的ＡＦＰ阳性肝癌细胞具有特异杀伤作用，而对ＡＦＰ阴性的肝癌细胞和非肝癌细胞无杀伤作用。结论在细胞水平实现了对ＡＦＰ阳性肝癌细胞的靶向性基因治疗。

Objective To investigate the α fetoprotein (AFP) specific promoter mediated target gene therapy of hepatocellular carcinoma in vitro. Methods Retroviral vector (LX2.2CD) in which the cytosine deaminase (CD) gene was driven by the 2.2 kb recombinant human AFP TRS. After transfecting three human hepatoma cell lines and one non hepatoma cell line with LX2.2 CD, anti G418 clones integrated CD gene were selected, and inhibitory experiment of cell growth was performed.Results 5 fluorocytosine (5FC) could confer the chemosensitivity to transduced AFP producing hepatoma cells (HuH 7 and huH 1/c1 2), but not to AFP nonproducing hepatoma cells (HLE) or nonhepatoma cells (GLC). On the other hand, when transfecting the above four tumor cell lines with another retroviral vector pCD2 (CD gene was driven by 5′LTR internal promoter), no cell selection was found in 5FC induced cell grow inhibition.Conclusions Recombinant retrovival transfer of the CD gene under the control of the AFP TRS followed by 5FC may well be a promising targeted gene therapy for hepatoma.