IMMUNOHISTOCHEMICAL STUDY SUGGESTING A COMPLEMENTARY ROLE OF KALLIKREINS HK2 AND HK3 (PROSTATE-SPECIFIC ANTIGEN) IN THE FUNCTIONAL-ANALYSISOF HUMAN PROSTATE TUMORS

The development of monoclonal antibodies directed against prostatic ka llikrein hK2 prompted us to evaluate Ifs content, along with that of h K3 (prostate-specific antigen), in human prostate carcinoma, Seventy t umors categorized according to the M.D. Anderson Hospital classificati on (grade I to IV) were analyzed by immunohistochemistry. The staining intensity or the kallikrein content of benign prostatic hyperplasia g landular tissue (used as control) and of grade I tumors appeared simil ar In grade II to IV tumors, histochemical data revealed highly variab le hK2 or hK3 content in approximately 25% of tumors, Such patterns ar e consistent with a current observation related to heterogeneity of pr ostate tumor's. In addition, a few tumors did not express hK3 (n = 3), hK2 (n = 3), or both (n = 3), indicating that some growth patterns of prostatic neoplasia are associated with a lack of secretion or storag e of hK3 or hK2 for immunodetection, This statement also appears relev ant to metastases. It was interesting to note that 4% of hK3-negative tumors had detectable hK2, Because of the importance of hK3 as a serum marker of prostate disorder, this study addresses for the first time the question of the relative importance of both hK3 and hK2 in the imm unohistochemical diagnosis of prostatic tumors, We conclude that hK2 m ay add new information to prostate cancer diagnosis and characterizati on.