Down -regulation of prostate specific antigen in human CWR22 xenograft: An ex vivo tumor model for prostate cancer gene therapy

L. Cheng, J. Sun, T. G. Pretlow, J. Decker, N. S. Yang

Research output: Contribution to journalArticle

Abstract

We evaluated in this study the application of an ex vivo gene transfer approach for human prostate cancer gene therapy. We constructed and established a transgenic human tumor model, consisting of three major components: 1) human primary prostate cancer cells, a recently reported androgen-dependent, transplantable xenograft (CWR22), derived from a primary human prostate carcinoma, 2) a coflagen gel, ex vivo tissue culture system effective for short-term maintenance and manipulation of CWR22 cells under in vitro conditions, and 3) a particle-mediated gene transfer delivery system highly efficient for the a vivo transfection of these cells. With the luciferase reporter gene, twenty- to thirty-fold higher levels of Iransgene expression were observed when CWR22 cells were embedded and Iransfected in the collagen gel matrix, as compared to test cells suspended in culture medium or loosely attached to plastic substratum. Up to 10% gene gun treated cells express β-galactosidase activity. Candidate therapeutic genes, including human interleukin-2 (IL-2) and granulocyte-macrophage colonystimulating factor (GM-CSF), were expressed at high levels (up to 38 ng/106 cell/24 hour). Cytokine transgene expression was sustained at approximately 40-50% of peak levels during the entire experimental period (9-10 days in culture). At 7 days post-gene delivery, a more than two-fold reduction in the secretion of prostate specific antigen (PS A) was detected in the IL-2 or GM-CSF cDNA transfected cells, as compared to the luciferase cDNA transfected control cells. Three dimensional organization of tumor cells was maintained in this ex vivo tumor model. The findings suggest that me current in vitro/ex vivo human prostate tumor model system may be effectively employed as an ex vivo model for gene therapy of human prostate cancer, especially for evaluating the cancer vaccine approach.

Original languageEnglish (US)
Pages (from-to)A1143
JournalFASEB Journal
Volume10
Issue number6
StatePublished - Dec 1 1996
Externally publishedYes

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ASJC Scopus subject areas

  • Biotechnology
  • Biochemistry
  • Molecular Biology
  • Genetics

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