DEVELOPMENT OF PROSTATE-SPECIFIC ANTIGEN PROMOTER-BASED GENE THERAPY FOR ANDROGEN-INDEPENDENT HUMAN PROSTATE CANCER Academic Article uri icon

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abstract

  • PURPOSE: The goal of this study is to develop a tissue-specific toxic gene therapy utilizing the prostate specific antigen (PSA) promoter for both androgen-dependent (AD) and androgen-independent (AI) PSA-secreting prostate cancer cells. Ideally this gene therapy would be effective without the necessity of exposing the target cells to circulating androgens. MATERIALS AND METHODS: An AI subline of LNCaP, an AD PSA-secreting human prostate cancer cell line, C4-2, was used in this study. Castrated mice bearing C4-2 tumors secrete PSA. A transient expression experiment was used to analyze the activity of two PSA promoters, a 5837 bp long PSA promoter and a 642 bp short PSA promoter, in C4-2 cells. A recombinant adenovirus (Ad-PSA-TK) carrying thymidine kinase under control of the long PSA promoter was generated. The tissue-specific activity of Ad-PSA-TK was tested in vitro and in vivo. RESULTS: The long PSA promoter had superior activity over short PSA promoter, and higher activity in C4-2 cells than in LNCaP cells. High activity of Ad-PSA-TK was observed in C4-2 cells in an androgen deprived condition. In vitro, Ad-PSA-TK was further demonstrated to induce marked C4-2 cell-kill by acyclovir in medium containing 5% FBS. No cell-kill was observed in control WH cells (a human bladder cancer cell line). In vivo, Ad-PSA-P-TK with acyclovir significantly inhibited subcutaneous C4-2 tumor growth and PSA production in castrated animals. CONCLUSION: The 5837 bp long PSA promoter was active in the androgen free environment and could be used to target both androgen-dependent and independent PSA-producing prostate cancer cells in vitro, and prostate tumors in castrated hosts.

authors

  • Graham, Frank Lawson
  • GOTOH, AKINOBU
  • KO, SONG-CHU
  • SHIRAKAWA, TOSHIRO
  • CHEON, JUN
  • KAO, CHINGHAI
  • MIYAMOTO, TADAYUKI
  • GARDNER, THOMASA
  • HO, LING-JUN
  • CLEUTJENS, CATHARINABJ
  • TRAPMAN, JAN
  • GRAHAM, FRANKL
  • CHUNG, LELANDWK

publication date

  • July 1998