Macrophage migration inhibitory factor in prostatic adenocarcinoma: Correlation with tumor grading and combination endocrine treatment-related changes

BACKGROUND. Macrophage migration inhibitory factor (MIF) is a ubiquitary cy tokine whose expression has been investigated in tumors, showing a correlat ion between tumor aggressiveness and production of this protein by neoplast ic cells. The aim of our study was to correlate MIF expression with tumor g rade (Gleason scoring system) and histopathological changes after combined endocrine treatment (CET) of prostate adenocarcinoma. METHODS. We analyzed MIF immunoreactivity in 124 paired needle biopsies and radical prostatectomy specimens from 62 prostate cancer patients, of which 20 had been treated with CET. RESULTS. In untreated prostates, MIF expression significantly correlated wi th tumor grading, being stronger in low-grade than in high-grade adenocarci noma. In treated prostates, histopathological changes also correlated with MIF immunoreactivity, but not in a significant manner. CONCLUSIONS. The results of the current study demonstrated that with histol ogical dedifferentiation, prostate adenocarcinoma cells show a reduced MIF expression. This finding may be the consequence of a reduced MIF synthesis or the result of an enhanced and altered secretion by tumor cells into the surrounding stroma. The consequent abnormal interaction between MIF and env ironmental factors might influence tumor growth and diffusion. On the other hand, the minor but not significantly reduced MIF expression by tumor cell s after CET seems to exclude a hormonal regulation of MIF secretion. (C) 20 00 Wiley-Liss, Inc.