Immunohistochemical expression of transforming growth factor beta 1 and nm-23 H1 antioncogene in prostate cancer: divergent correlation with clinicopathological parameters.

BACKGROUND

Prostate cancer is one of the main causes of morbidity and mortality among men. Several oncogenes and growth factors have been studied in an attempt to explain the molecular basis of carcinogenesis and progress of this carcinoma. In this study we correlated the immunohistochemical expression of antioncogene nm-23 H1 and transforming growth factor beta 1 (TGF-beta 1) with the clinical stage, PSA values, Gleason score and survival in prostate cancer.

MATERIALS AND METHODS

Fifty nine patients with prostate cancer were evaluated. PSA measurement, Gleason score determination and clinical staging were recorded for all the patients by the time of initial diagnosis and prior to any treatment. Follow-up ranged from 12 to 40 months. Tissue sections from representative areas of the tumors were immunohistochemically stained for nm-23 H1 and TGF-beta 1. The expression of these markers was correlated with stage, PSA values, Gleason score and survival.

RESULTS

There was a negative correlation between nm-23 H1 staining and tumor stage and grade. High grade (Gleason score 8-10) and stage D tumors showed weaker staining than low stage and grade tumors. There was a positive correlation between TGF-beta 1 staining, tumor stage and serum PSA levels. Additionally, TGF-beta 1 proved to be a negative predicting factor for patient survival. In tumors expressing both markers, TGF-beta 1 was the one to determine the aggressiveness of the carcinoma.

CONCLUSIONS

nm-23 H1 appears to be a tumor suppressor gene in prostate cancer, while TGF-beta 1 may act as a stimulating agent provoking aggressive behavior and metastasis. Their immunohistochemical staining may constitute complementary information in the evaluation of prostate cancer patients.