Inhibition of the growth of pre‐established subcutaneous tumor nodules of human prostate cancer cells by single injection of the recombinant adenovirus p53 expression vector

We have previously described potent growth‐inhibitory effect of a recombinant adenovirus expressing wild type p53 (AdWTp53) in metastatic prostate cancer cells via activation of cellular p53 pathways. We have extended these observations to analyze the effects of AdWTp53 on primary cultures of radical prostatectomy specimens (RPS) and have also evaluated the gene therapeutic potential of the AdWTp53 in a nude mice model. Infection of primary cultures of prostate cancer specimens resulted in about 80% cell growth inhibition in comparison with cultures treated with control adenovirus dl312. Single injection of AdWTp53 into pre‐established tumor nodules of DU145 prostate cancer cells suppressed tumor growth significantly (p = 0.0407) as determined by comparison of tumor volumes of the AdWTp53‐treated vs. control vector (dl312) or PBS‐treated groups. Moreover, there was no significant difference in tumor growth inhibition between single vs. multiple injections of AdWTp53. Our observations support the potential of AdWTp53 for gene therapy of prostate cancer. Int. J. Cancer 71:377‐382, 1997. © 1997 Wiley‐Liss Inc.