Evidence for prostate cancer-associated diagnostic marker-1: immunohistochemistry and in situ hybridization studies.

PURPOSE: The purpose of this study was to characterize a novel gene/protein associated with prostate cancer, termed prostate cancer-associated diagnostic marker-1 [PCADM-1 (Hu Y, Wang M, Garcia FU, Aoyaki K, Stearns ME. Identification of PCADM-1 as a novel diagnostic marker for prostate cancer, submitted for publication)]. EXPERIMENTAL DESIGN AND RESULTS: Immunological studies revealed that rabbit polyclonal antibodies generated against recombinant PCADM-1 specifically recognize the protein in crude protein extracts from a variety of prostate cancer cell lines (i.e., PC-3 ML, LNCaP, DU145, and CPTX-1532) and prostate cancer tissue. Combined immunolabeling and in situ hybridization studies demonstrated that PCADM-1 mRNA was expressed by the luminal epithelial cells of prostate cancer glands and was not expressed by high-grade prostatic intraepithelial neoplasia or HPV-MLC7 cells. Immunolabeling studies of tissue arrays from biopsies of archival material (n = 200 samples) confirmed that PCADM-1 was expressed by the luminal epithelial cells of prostate cancer. CONCLUSIONS: Taken together, the data suggest that PCADM-1 is a specific marker for human prostate cancer.