[Expression of type I and type II 5alpha-reductase isoenzymes in prostate cancer tissues]

To study the relative tissue distribution and expression pattern of type I and type type II 5alpha-reductase isozymes in prostate cancer tissues.

Immunohistochemistry and RT-PCR method were used to investigate qualitatively and semi-quantitatively the expression of type I and type II 5alpha-reductases in prostate tissues from 15 normal persons and 15 patients with prostate cancer.

Two isozymes were detected in both normal and cancerous prostate tissues with the two methods. Both 5alpha-reductases were mainly localized in the cytoplasm, and higher degree of staining was observed in epithelial cells than in stroma. Significantly higher level of type I 5alpha-reduetase expression was observed in cancerous tissue than in normal tissue. The expression level of type I 5alpha-reduetase was positively correlated with the tumor stage and grade, and serum PSA concentration. The expression of type II 5alpha-reductase was very weak in prostate cancer tissue.

The type I 5alpha-reductase, not type II, is involved in the pathogenesis of protate cancer. Selective type I 5alpha-reductase inhibitors or dual inhibitors of both type human 5alpha-reductase isoforms can be used in the treatment of prostate cancer.