[Expression of cellular FLICE inhibitory protein (cFLIP) in endometrial adenocarcinoma]

Cellular FLICE inhibitory protein (cFLIP) is a new-found member of the inhibitors of apoptosis. It has been reported to be overexpressed in various human cancers. We investigated the expression of cFLIP in endometrial adenocarcinoma and its association with clinicopathological features and proliferating cell nuclear antigen-labeling index (PCNA-LI).

cFLIP and PCNA-LI were determined in endometrial tissue samples including 42 endometrial adenocarcinoma tissues, 20 normal proliferative endometrial tissues, and 40 hyperplastic tissues with (n=10) or without (n=30) atypia by immunohistochemistry.

The positive rates of cFLIP expression in normal proliferative samples of endometrium, hyperplastic samples, and endometrial adenocarcinomas were (55.0+/-11.4)%, (72.5+/-7.1)%, and (83.3+/-5.8)%, respectively. Scoring on the basis of the percentage of positive cells and the intensity of positive immunostaining indicated that the expression level of cFLIP was significantly higher in adenocarcinoma than in normal proliferative endometrium (P< 0.01) and hyperplastic endometrium with or without atypia (P< 0.05);but no significant difference was found between the later two groups. PCNA-LI were (12.01+/-2.07)%,(20.26+/-6.99)%, (27.10+/-3.01)%, and (41.65+/-10.16)%, respectively in the adenocarcinoma groups with different cFLIP levels showed as -, +, ++, +++. Statistical analysis showed that cFLIP expression was significantly associated with PCNA-LI (r=0.7471,P< 0.01). In addition, cFLIP expression was also significantly associated with clinical stage (P< 0.05), the presence of invasion to >1/2 myometrium (P< 0.05) and positive lymph node metastasis (P< 0.01) of endometrial adenocarcinomas.

Overexpression of cFLIP is tumor specific, which may be a late event in the tumor development of endometrial adenocarcinoma.