Expression Analysis of c-IAP2 in Ovarian Carcinomas

Cho, Chi Heum; Cha, Soon Do; Baek, Won Ki; Kwon, Kun Young; Bae, In Soo

Abstract

OBJECTIVE
Apoptosis or programmed cell death is a normally physiological cell suicide program that is highly conserved among all animals. We previously evaluated overexpression of c-IAP1(Inhibitor of Apoptosis Protein) in ovarian carcinomas compared with normal ovaries. In this study, we demonstrate evidence for the involvement of c-IAP2 in ovarian carcinomas.
METHODS
Fresh 9 normal ovaries, 5 benign ovarian cysts and 13 ovarian carcinomas were obtained from routine gynecologic surgeries carried out for benign and malignant ovarian tumors. They were examined for the presence of c-IAP2 by RT-PCR(Reverse Transcriptase Polymerase Chain Reaction), Western blot analysis and immunohistochemical stains.
RESULTS
Nine of 14 normal and benign ovarian tumors were negative and 11 of 13 ova rian carcinomas were positive for c-IAP2 by RT-PCR. Positive RT-PCR for c-IAP2 was seen in 11/13 of ovarian carcinomas, a significantly higher percentage than in normal and benign ovarian tumors(5/14). All of these tumors showed strong positive for c-IAP2 by western blot and immunohistochemical staining. Whereas negative RT-PCR for c-IAP2 was seen in 9/14 of normal and benign ovarian tumors, a significantly higher percentage than ovarian carcinomas(2/13). Of these 9 negative samples, 6 had positive Western blot and immunohistochemical stains. There was weak concordance of the result. But expression of c-IAP2 in normal ovarian tissue was localized exclusively in the corpus luteum. Therefore, c-IAP2 may play important role in determining the fate of the follicular destiny. There was no expression in normal ovarian stroma cells for c-IAP2.
CONCLUSIONS
These findings suggest that c-IAP2 is expressed in ovarian carcinomas and emerging role in cancer. The c-IAP2 expression has been investigated in the normal ovary, where apoptosis is thought to play an important role in ovulation.