Huber B E, Richards C A, Krenitsky T A
Division of Experimental Therapy, Wellcome Research Laboratories, Research Triangle Park, NC 27709.
Proc Natl Acad Sci U S A. 1991 Sep 15;88(18):8039-43. doi: 10.1073/pnas.88.18.8039.
An approach involving retroviral-mediated gene therapy for the treatment of neoplastic disease is described. This therapeutic approach is called "virus-directed enzyme/prodrug therapy" (VDEPT). The VDEPT approach exploits the transcriptional differences between normal and neoplastic cells to achieve selective killing of neoplastic cells. We now describe development of the VDEPT approach for the treatment of hepatocellular carcinoma. Replication-defective, amphotrophic retroviruses were constructed containing a chimeric varicella-zoster virus thymidine kinase (VZV TK) gene that is transcriptionally regulated by either the hepatoma-associated alpha-fetoprotein or liver-associated albumin transcriptional regulatory sequences. Subsequent to retroviral infection, expression of VZV TK was limited to either alpha-fetoprotein- or albumin-positive cells, respectively. VZV TK metabolically activated the nontoxic prodrug 6-methoxypurine arabinonucleoside (araM), ultimately leading to the formation of the cytotoxic anabolite adenine arabinonucleoside triphosphate (araATP). Cells that selectively expressed VZV TK became selectively sensitive to araM due to the VZV TK-dependent anabolism of araM to araATP. Hence, these retroviral-delivered chimeric genes generated tissue-specific expression of VZV TK, tissue-specific anabolism of araM to araATP, and tissue-specific cytotoxicity due to araM exposure. By utilizing such retroviral vectors, araM was anabolized to araATP in hepatoma cells, producing a selective cytotoxic effect.
描述了一种涉及逆转录病毒介导的基因疗法用于治疗肿瘤疾病的方法。这种治疗方法被称为“病毒导向酶/前药疗法”（VDEPT）。VDEPT方法利用正常细胞和肿瘤细胞之间的转录差异来实现对肿瘤细胞的选择性杀伤。我们现在描述VDEPT方法用于治疗肝细胞癌的进展。构建了复制缺陷型、双嗜性逆转录病毒，其包含嵌合的水痘-带状疱疹病毒胸苷激酶（VZV TK）基因，该基因由肝癌相关的甲胎蛋白或肝脏相关的白蛋白转录调控序列进行转录调控。在逆转录病毒感染后，VZV TK的表达分别局限于甲胎蛋白阳性或白蛋白阳性细胞。VZV TK代谢激活无毒前药6-甲氧基嘌呤阿拉伯核苷（araM），最终导致细胞毒性代谢物腺嘌呤阿拉伯核苷三磷酸（araATP）的形成。由于araM通过VZV TK依赖性合成代谢转化为araATP，选择性表达VZV TK的细胞对araM变得选择性敏感。因此，这些逆转录病毒递送的嵌合基因产生了VZV TK的组织特异性表达、araM到araATP的组织特异性合成代谢以及由于暴露于araM而产生的组织特异性细胞毒性。通过利用这种逆转录病毒载体，araM在肝癌细胞中被合成为araATP，产生了选择性细胞毒性作用。
