EXPRESSION OF NM23-H1 IN PROSTATIC INTRAEPITHELIAL NEOPLASIA AND ADENOCARCINOMA

The product of the nm23-H1 gene has been reported to be related to the metastatic potential of several tumors. Although several studies have characterized the expression of the nm23-H1 gene product in prostatic adenocarcinoma, little is known of the expression of this protein in prostatic intraepithelial neoplasia (PIN), a putative precancerous les ion, The authors used immunohistochemistry to examine the expression o f the nm23-H1 protein in PIN as well as benign and malignant prostatic tissue. A monoclonal antibody to nm23-H1 (Novocastra, Newcastle upon Tyne, UK, clone 37.6) and a biotin/strepavidin detection system were u sed for antigen localization. Weak to moderate immunostaining was cons istently detected in the benign glandular epithelium of 28 radical pro statectomy specimens. In contrast, strong immunostaining was detected in the glandular epithelium in PIN lesions of 19 radical prostatectomy specimens examined, Strong immunostaining was also frequently detecte d in the malignant cells of 39 localized prostatic adenocarcinomas, as well as 7 metastatic lesions. These findings show a phenotypic simila rity of PIN to prostatic adenocarcinoma with respect to nm23-H1 expres sion. Furthermore, strong expression of nm23-H1 likely represents an e arly event in the development of prostatic adenocarcinoma. Copyright ( C) 1996 by W.B. Saunders Company