Blackburn R V, Galoforo S S, Corry P M, Lee Y J
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan 48073-6769, USA.
Cancer Res. 1998 Apr 1;58(7):1358-62.
Tumor cells that express a fusion gene comprised of Escherichia coli cytosine deaminase (CD) and herpes simplex virus type 1 thymidine kinase (TK) sequences exhibit activation of and subsequent killing by the normally innocuous prodrugs 5-fluorocytosine and ganciclovir (Rogulski et al., Hum. Gene Ther., 8: 73-85, 1997). To target localized expression of this therapeutic gene, we have constructed a recombinant adenovirus containing the CD-TK fusion gene under the control of a human inducible heat shock protein 70 promotional sequence. Strong expression of the fusion gene product was induced by heating at 41 degrees C for 1 h. Expression levels obtained were dependent on the multiplicity of infection used and the incubation time after heat shock. Heat-induced expression of the CD-TK protein significantly reduced the survival of PC-3 cells in the presence of both 5-fluorocytosine and ganciclovir. These studies represent a novel form of gene therapy for the transduction and regulation of a double suicide gene in tumor cells and may provide a unique application for hyperthermia in cancer therapy.
表达由大肠杆菌胞嘧啶脱氨酶（CD）和单纯疱疹病毒I型胸苷激酶（TK）序列组成的融合基因的肿瘤细胞，在接触通常无害的前体药物5-氟胞嘧啶和更昔洛韦后，会出现激活并随后被杀死的情况（Rogulski等人，《人类基因治疗》，8: 73 - 85, 1997）。为了靶向该治疗性基因的局部表达，我们构建了一种重组腺病毒，其包含在人诱导型热休克蛋白70启动子序列控制下的CD - TK融合基因。通过在41摄氏度加热1小时诱导融合基因产物的强烈表达。获得的表达水平取决于所用的感染复数和热休克后的孵育时间。在同时存在5-氟胞嘧啶和更昔洛韦的情况下，热诱导的CD - TK蛋白表达显著降低了PC - 3细胞的存活率。这些研究代表了一种用于肿瘤细胞中双自杀基因转导和调控的新型基因治疗形式，并且可能为热疗在癌症治疗中的独特应用提供依据。
