WESTERN-BLOT ASSAY FOR PROSTATE-SPECIFIC MEMBRANE ANTIGEN IN SERUM OFPROSTATE-CANCER PATIENTS

There is a need for the development of new diagnostic tools for the ea rly detection of prostate cancer. A candidate molecule for a new scree ning test is a prostatic-specific membrane antigen (PSM) recognized by the monoclonal antibody 7E11.C5. We carried out studies aimed at iden tifying PSM in the serum of normal and benign prostatic hyperplasia (B PH) donors and patients with adenocarcinoma of the prostate, in order to judge whether the development of a serum assay using this marker wa s feasible. By Western blotting, we found significant levels of PSM in serum samples from prostatic cancer patients, in the seminal fluid of pooled normal donors, in BPH patients, and in normal male sera. Simil ar to prostate-specific antigen (PSA), PSM was present in seminal plas ma in higher concentrations than in serum, and PSM levels in prostatic cancer patients were significantly higher than in normal controls. Th ese data suggest that the development of an assay utilizing the PSM an d new monoclonal antibodies directed against the antigen, could provid e a feasible test for prostatic cancers. (C) 1994 Wiley-Liss, Inc.