The inhibitor of apoptosis proteins (IAPs) constitutes a family of highly conserved apoptosis suppressor proteins that were originally identified in baculoviruses. Although IAP homologs have recently been demonstrated to suppress apoptosis in mammalian cells, their expression and role in human gynecologic cancers are unknown. In this study auther used ovarian and cervical cancer tissues to examine the role of IAP in the regulation of apoptosis in cervical and ovarian cancers compared with normal tissues.

Fresh tissues were retrieved from 10 cases each with ovarian cancers, cervical cancers and 4 normal ovarian tissues, 6 benign ovarian tumors, and 10 normal cervical tissues. Expression of mRNA was determined by RT-PCR. Western blot analysis was also used for asseessment of protein expression.

The overexpression of c-IAP1,2 was identified in ovarian cancers compare with normal ovaries. All cases of cervical cancer tissues were negative and normal cervical tissues were positive for c-IAP1,2 by RT-PCR assay. Using Western blot analysis, the overexpression of c-IAP1,2 was observed in ovarian cancer tissues compared with normal ovarian tissues and overexpression of c-IAP1 in normal cervical tissues. However differences were not observed with expression of c-IAP2 in cervical cancer tissues. On immunohistochemical results, the expression of c-IAP1,2 was observed in ovarian cancer tissues, normal corpus luteum, and normal cervical tissues, whereas c-IAP1 was not shown in cervical cancer tissues. There was no correlation in c-IAP2 expression between cervical cancer and normal cervical tissues.

These results suggest that c-IAP1,2 are important elements in growth of ovarian cancers, whereas c-IAP1 may play role of down regulation to cervical carcinogenesis.