Beck C, Cayeux S, Lupton S D, Dörken B, Blankenstein T
Robert-Rössle Klinik, Virchow Klinikum der Medizinichen Fakultät der Humboldt Universität Berlin, Germany.
Hum Gene Ther. 1995 Dec;6(12):1525-30. doi: 10.1089/hum.1995.6.12-1525.
The herpes simplex virus thymidine kinase (HSV-TK) converts ganciclovir (GCV) into a toxic product and allows selective elimination of TK+ cells in vitro and in vivo. It is currently being used in clinical gene therapy trials as a therapeutic gene or as a safety marker. We have analyzed the susceptibility of different tumor cell lines to the TK/GCV-mediated "suicide" effect. Therefore, tumor cells TSA, J558L, EB, and ESB and, as a control, NIH-3T3 cells were infected with a retrovirus containing a hygromycin/TK fusion gene. All cell lines were sensitive to GCV in vitro; however, the concentration of GCV and the time needed to eliminate tumor cells completely considerably varied between different tumor cell lines. TSA-TK cells were completely eliminated within 10 days in 1 microg/ml GCV, whereas ESB-TK cells required 22 days in 10 microg/ml GCV. When two cell lines were examined, the differing sensitivity to GCV in vitro correlated with the ability to eradicate TK+ tumors in vivo. TSA-TK tumors could be eliminated in almost all animals by systemic GCV administration, whereas ESB-TK tumors were completely resistant. Different sensitivity to GCV was not due to different TK expression levels because the cells were similarly resistant to hygromycin, and Western blot analysis with an anti-TK antiserum revealed similar protein amounts in TSA/TK and ESB-TK cells. Together, the results demonstrate that tumor cells are highly different concerning the susceptibility to the TK/GCV effect, which, however, may be tested for in vitro.
单纯疱疹病毒胸苷激酶（HSV-TK）可将更昔洛韦（GCV）转化为有毒产物，从而在体外和体内实现对TK+细胞的选择性清除。目前，它作为治疗基因或安全标记物正用于临床基因治疗试验。我们分析了不同肿瘤细胞系对TK/GCV介导的“自杀”效应的敏感性。因此，用含潮霉素/TK融合基因的逆转录病毒感染肿瘤细胞TSA、J558L、EB和ESB，并以NIH-3T3细胞作为对照。所有细胞系在体外对GCV均敏感；然而，不同肿瘤细胞系完全清除肿瘤细胞所需的GCV浓度和时间差异很大。TSA-TK细胞在1μg/ml GCV中10天内被完全清除，而ESB-TK细胞在10μg/ml GCV中需要22天。当检测两种细胞系时，体外对GCV的不同敏感性与体内根除TK+肿瘤的能力相关。通过全身给予GCV，几乎所有动物体内的TSA-TK肿瘤都可被清除，而ESB-TK肿瘤则完全耐药。对GCV的不同敏感性并非由于TK表达水平不同，因为细胞对潮霉素的耐药性相似，并且用抗TK抗血清进行的蛋白质印迹分析显示TSA/TK和ESB-TK细胞中的蛋白量相似。总之，结果表明肿瘤细胞对TK/GCV效应的敏感性差异很大，但这可以在体外进行检测。
