title: Enhanced suicide gene therapy by chimeric tumor-specific promoter based on HSF1 transcriptional regulation.
abstract: Two tandem cassettes, one containing the telomerase reverse transcriptase gene (hTERT) promoter upstream of a constitutively activated form of heat shock transcription factor 1 (cHSF1) and followed by the other containing the heat shock protein 70B (hsp70B) promoter (HSE) upstream of the cytosine deaminase (CD) gene, could greatly enhance the efficiency of CD gene therapy while retaining tumor specificity in vitro and in vivo. This hTERT-cHSF1/HSE promoter could restrict gene expression in tumor cells and was about 1.5-3-fold more potent than the cytomegalovirus (CMV) promoter. hTERT-cHSF1/HSE-CD transfection led to tumor cells more sensitive to 5-fluorocytosine compared with hTERT-CD and its toxicity was comparable to that of CMV-CD. Besides enhancement of promoter activity, cHSF1 overexpression itself could enhance the bystander effect of CD gene therapy that could be reversed by anti-Fas antibody. This system also led to activation of stress-related genes such as hsp70 in tumor cells, which in the presence of cell killing by the cytotoxic gene is a highly immunostimulatory event. Furthermore, a more potent anti-tumor effect of hTERT-cHSF1/HSE-CD was observed in nude mice inoculated with Bcap37 cells. No obvious activity of the hTERT-cHSF1/HSE promoter was observed in normal tissues after intravenous administration. These results indicate that the hTERT-cHSF1/HSE promoter is highly tumor-specific and strong with potential application in targeted gene therapy, and therefore may be useful for construction of vectors for systemic therapy.
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, PR China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Wang
authors.forename: Mingzhong
authors.initials: M
authors.lastname: Yao
authors.forename: Zilai
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jinfa
authors.initials: J
authors.lastname: Gu
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Binhua
authors.initials: B
authors.lastname: Li
authors.forename: Lanying
authors.initials: L
authors.lastname: Sun
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D024201:Bystander Effect; D003587:Cytomegalovirus / Q000235:genetics; D043525:Cytosine Deaminase; D004268:DNA-Binding Proteins / Q000502:physiology*; D015316:Genetic Therapy; D000076249:Heat Shock Transcription Factors; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009700:Nucleoside Deaminases / Q000378:metabolism; D000091402:Prohibitins; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000502:physiology*; D019098:Telomerase / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; C000717331:PHB2 protein, human; C000717333:Phb2 protein, mouse; D000091402:Prohibitins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D019098:Telomerase; D009700:Nucleoside Deaminases; D043525:Cytosine Deaminase