A putative prostate cancer marker called PC I has been identified in prostate cancers, but not in benign hyperplasia or normal prostate. We have produced specific anti PC I monoclonal antibodies, selected by immunofluorescent nuclear antigen localization on the PC I positive prostate tumor cell line LNCAP and l D immunoblots against LNCAP extracted nuclear matrix proteins. Following further characterization of PC I specific antibodies bv 2 D immunoblotting on nuclear matrix extracted from prostate cancer tissue, our goal is to evaluate the tissue specificity of PC I by immunohistochemical localization of PC I antigen in frozen sections of prostate tumor tissue, benign hyperplastic and normal prostate, as well as a panel of non prostate tissues.Antibodies selected for their ability to distinguish between cancerous and benign/normal prostate tissue will be used to search for PC I protein in urine or serum from prostate cancer patients by two site immunoassay. If tissue localization of PC I can distinguish cancer patients from those with benign disease, or if PC I is detectable in either serum or urine, then an immunoassay based upon the detection of this protein could improve patients management or could aid in the early detection of prostate cancer.Commercial ApplicationsProstate cancer is the second leading cause of cancer deaths in males. Current diagnosis relies upon pathological evaluation of biopsies and serum screening for prostate specific antigen (PSA), although PSA cannot distinguish between cancer and benign disease. We will assess the clinical utility of monoclonal antibodies specific for the prostate cancer marker PC I . A PC I based immunoassay which can distinguish between cancer and benign disease represents an improvement over PSA and would have a large commercial market value for prostate cancer diagnosis.National Cancer Institute (NCI)
