MONOCYTE CHEMOATTRACTANT PROTEIN-1 GENE-EXPRESSION IN PROSTATIC HYPERPLASIA AND PROSTATE ADENOCARCINOMA

Human monocyte chemoattractant protein-1 (MCP-1) has been shown to net as a chemokine in the recruitment of monocyte/macrophages during infl ammation states. Furthermore, there is increasing evidence that MCP-1 is involved in the recruitment of tumor-associated macrophages. In viv o, one of the major cellular sources of MCP-1 are the smooth muscle ce lls. As MCP-1 gene expression and/or protein production in these cells is not necessarily correlated with the accumulation of inflammatory c ells, there might possibly be additional functions of this cytokine. r n the present study, we investigated by use of S-35-labeled antisense RNA probes whether the MCP-1 gene is expressed in tissue specimens of benign prostatic hyperplasia (n = 13) and specimens of prostate carcin oma (n = 8), both of which are characterized by a prominent fibromuscu lar stroma and inconspicuous inflammatory infiltrates. MCP-1 transcrip ts were located in stromal smooth muscle cells and, additionally, itt basal cells of benign prostatic glands. In prostate carcinoma, the num ber of MCP-1 mRNA-expressing cells was significantly less than in beni gn prostatic hyperplasia. MCP-1 transcripts were located in preserved fibromuscular stroma and in basal cells of entrapped non-neoplastic gl ands but not in carcinomatous cells. Immunohistochemical staining with polyclonal antibodies raised against MCP-1 revealed strong reactivity in the fibromuscular stroma surrounding both benign and malignant gla nds MCP-1 gene expression or immunoreactivity for anti-MCP-1 antibodie s was trot related to the rare, lymphocytic interstitial infiltrates. The results show that 1) in the absence of significant leukocyte accum ulation, it is unlikely that MCP-1 exerts chemotactic functions in the prostate and 2) that MCP-1, in contrast to previous findings in a wid e variety of other human neoplasms, is not expressed in carcinomatous cells of the prostate.