Tumor angiogenesis is associated with MUC1 overexpression and loss of prostate-specific antigen expression in prostate cancer.

The biological potential of prostate cancer is highly variable and cannot be satisfactorily predicted by histopathological criteria alone. Therefore, additional and more precise information is desirable. Although angiogenesis has been suggested as being of prognostic importance in many human cancers, and MUC1, also known as episialin, was thought to be responsible for the development of metastasis, the role of these parameters in prostate cancer remains unclear. The aim of this study was to investigate whether angiogenesis, assessed as microvessel density (MVD), was correlated with the expression of prostate tumor MUC1 and prostate-specific antigen (PSA) or with histopathological grade at diagnosis, and to determine whether any of these factors might provide additional information with regard to prostate tumor biology. Paraffin-embedded material from 60 patients with prostate carcinoma was examined immunohistochemically, using the monoclonal antibody CD31 to determine MVD, and the monoclonal antibodies CCE831 and ER-PR8 to assess MUC1 and PSA expression, respectively. The tumors were categorized according to the Gleason grading system. MUC1 overexpression was significantly related to a high intratumoral angiogenesis (P = 0.02). By contrast, a high PSA expression by prostate cancer cells was associated with low MVD (P = 0.03). No correlation was found between MUC1 and PSA expression. Usually, high-grade tumors were not PSA-expressive and tended to display increased angiogenesis. These differences, however, were not of statistical significance. Similarly, there was no statistically significant association between histological grade and MUC1 expression or angiogenesis. It is suggested that PSA may have a direct suppressive effect on new blood vessel formation in prostate cancer, whereas the expression of MUC1 in this tumor may be connected with an angiogenic phenotype. Additional studies are obviously needed to clarify the precise role of these proteins in prostate cancer.