COEXPRESSION OF PC2 AND PROENKEPHALIN IN HUMAN TUMORAL ADRENAL-MEDULLARY TISSUES

Expression of PC2, a Kex2-related protease, and of one of its possible substrates, proenkephalin, was examined in normal adrenal glands (n = 7) and pheochromocytomas (n = 20). PC2 could only be detected in norm al adrenal glands using the sensitive RT/PCR technique. By Northern bl ot, PC2 and proenkephalin were expressed in 85% and 90% of the 20 pheo chromocytomas studied, respectively. Moreover, in situ hybridization a nd immunohistochemistry confirmed expression of PC2 in human tumoral a drenal medullary tissue. These results show for the first time express ion of PC2 in human pheochromocytomas which may be involved in the pro cessing of proenkephalin.