Gene therapy for prostate cancer: Where are we now?

Purpose: The ability to recombine specifically and alter DNA sequences followed by techniques to transfer these sequences or even whole genes into normal and diseased cells has revolutionized medical research and ushered the clinicians of today into the age of gene therapy. We provide urologists a review of relevant background information, outline current treatment strategies and clinical trials, and delineate current challenges facing the field of gene therapy for advanced prostate cancer. Materials and Methods: We comprehensively reviewed the literature, including PubMed and recent abstract proceedings from national meetings, relevant to gene therapy and advanced prostate cancer. We selected for review literature representative of the principal scientific background for current gene therapy strategies and National Institutes of Health Recombinant DNA Advisory Committee approved clinical trials. Results: Current prostate cancer gene therapy strategies include correcting aberrant gene expression, exploiting programmed cell death pathways, targeting critical cell biological functions, introducing toxic or cell lytic suicide genes, enhancing the immune system antitumor response and combining treatment with conventional cytotoxic chemotherapy or radiation therapy. Conclusions: Many challenges lie ahead for gene therapy, including improving DNA transfer efficiency to cells locally and at distant sites, enhancing levels of gene expression and overcoming immune responses that limit the time that genes are expressed. Nevertheless, despite these current challenges it is almost certain that gene therapy will be part of the urological armamentarium against prostate cancer in this century.