Survivin, Possible Marker and Prognostic Factor in Oral Squamous Cell Carcinomas

Survivin is a member of the inhibitors of apoptosis (IAP) family that have been known to inhibit activated caspases in apoptosis. In contrast to most IAP family members, survivin mRNA is expressed during fetal development, is not found in normal adult tissues and is overexpressed again in the cancer. Though survivin expression has been documented in most human cancers, little is known about its expression in OSCC and its potential value as a predictor of cancer survival. The purpose of this study was to investigate survivin expression in OSCC and to evaluate its value as a prognostic marker. We evaluated survivin expressions in cancer lines and OSCC samples and investigated the relationships between survivin expressions and clinico-pathological parameters including stage, differentiation, proliferation, lymph node metastasis, blood vessel density, and gelatinolytic activity. With immunohistochemistry, we analyzed survivin expression in 38 OSCCs. Patients'clinico-pathological parameters and their survival rate were analyzed to reveal their correlations with Survivin expressions. We cultured oral cancer cell lines and evaluated the correlation between gelatinolytic activities and survivin expressions of them. Survivin protein was observed both in nuclei and cytoplasm of tumor specimens while little or not observed in normal gingival mucosal tissues. Additionally, survivin expressions were correlated with lymph node metastasis, tumor proliferation and survival rate. Survivin expression was observed in 100% of 38 samples of OSCC and its expression levels are statistically associated with the proliferative activity of the tumors, lymph node metastasis and the survival of the patients. Based on these results, survivin is commonly expressed in OSCC and may thus provide valuable prognostic information related with lymph node metastasis, proliferation and survival rate as well as a potential therapeutic target in OSCC.