Enhanced suicide gene therapy by chimeric tumor-specific promoter based on HSF1 transcriptional regulation

FEBS Lett. 2003 Jul 10;546(2-3):315-20. doi: 10.1016/s0014-5793(03)00606-9.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bystander Effect*
  • Cytomegalovirus / genetics
  • Cytosine Deaminase
  • DNA-Binding Proteins / physiology*
  • Genetic Therapy*
  • Heat Shock Transcription Factors
  • Humans
  • Mice
  • Mice, Nude
  • Nucleoside Deaminases / metabolism
  • Promoter Regions, Genetic*
  • Recombinant Fusion Proteins / physiology*
  • Telomerase / genetics
  • Telomerase / metabolism
  • Transcription Factors
  • Transcription, Genetic / physiology*
  • Tumor Cells, Cultured

Substances

  • DNA-Binding Proteins
  • HSF1 protein, human
  • Heat Shock Transcription Factors
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Telomerase
  • Nucleoside Deaminases
  • Cytosine Deaminase