Evrard A, Cuq P, Robert B, Vian L, Pèlegrin A, Cano J P
Laboratoire de Toxicologie du Médicament, Faculté de Pharmacie, Montpellier, France.
Int J Cancer. 1999 Jan 29;80(3):465-70. doi: 10.1002/(sici)1097-0215(19990129)80:3<465::aid-ijc21>3.0.co;2-6.
Transferring a gene into cancer cells in order to sensitize them to drugs is an important approach in human cancer gene-therapy research. Thymidine phosphorylase (TP) is the first enzyme in the metabolic activation pathway of 5-fluorouracil (5-FU) to fluorodeoxyribonucleotides, thus, it could be used to increase the sensitivity of cancer cells to this anti-pyrimidine agent. In this study, an expression vector containing the human TP cDNA was transfected into C26 murine colon-carcinoma cells. Stable transfectants were selected; all showed increased TP activity, ranging from 2- to 10-fold when compared with wild-type cells. The in vitro sensitivity of transfectants to 5-FU and 5'-deoxy-5-fluorouridine (5'-DFUR) was enhanced, in agreement with the observed increase in TP activity. Then, tumors were generated by s.c. injection of TP-transfected or wild-type C26 cells in syngeneic BALB/c mice. 5-FU (25 mg/kg, i.p.) induced a growth delay of TP-transfected C26 tumors as compared with C26 wild-type tumors. These data suggest that TP could be transfected in tumor cells to increase the sensitivity to 5-FU for subsequent cancer gene therapy.
将基因导入癌细胞使其对药物敏感是人类癌症基因治疗研究中的一种重要方法。胸苷磷酸化酶（TP）是5-氟尿嘧啶（5-FU）代谢激活途径中生成氟代脱氧核糖核苷酸的首个酶，因此，它可用于提高癌细胞对这种抗嘧啶药物的敏感性。在本研究中，将含有人TP cDNA的表达载体转染至C26小鼠结肠癌细胞中。筛选出稳定转染子；与野生型细胞相比，所有转染子的TP活性均增加了2至10倍。转染子对5-FU和5'-脱氧-5-氟尿苷（5'-DFUR）的体外敏感性增强，这与观察到的TP活性增加一致。然后，通过皮下注射TP转染的或野生型C26细胞在同基因BALB/c小鼠中生成肿瘤。与C26野生型肿瘤相比，5-FU（25 mg/kg，腹腔注射）诱导TP转染的C26肿瘤生长延迟。这些数据表明，TP可转染至肿瘤细胞中以提高对5-FU的敏感性，用于后续的癌症基因治疗。
