Survivin: a novel negative regulator of apoptosis in normal, dysplastic and malignant epithelium

ABSTRACT

Survivin is a bifunctional protein that suppresses apoptosis and regulates cell division. In particular, deregulation of apoptosis resulting in aberrantly reduced cell death is thought to participate in cancer by facilitating the uprising of additional transforming mutations. The aim of this study was to investigate the surviyin expression in normal oral epithelium, oral dysplastic lesions verrucous carcinomas, oral squamous cell carcinomas and metastatic carcinomas. 35 samples for the previous different lesions were collected. Paraffin sections were immunohistochemically stained using comercially available anti-survivin antibody. Survivin expression was semi-quantitatively evaluated in different lesions. In normal oral mucosa, survivin was mildly detected in all cases and mainly located in basal cell layer, both nuclear and cytoplasmic staining could be detected. Survivin expression increased with the progress of the grade of dysplasia. In all studied cases of verrucous carcinoma, - survivin staining showed a heterogeneous distribution. In oral squamous cell carcinoma, the greatest expression of survivin positivity was found in well differentiated carcinoma. Less well differentiated tumors and cases of poorly differentiated carcinoma revealed a lower degree of positivity. Metastatic carcinoma revealed mild to moderate homogenous intensity. Areas of individual necrotic tumor cells did not stain positive for survivin. Analysis of the data presented here suggests that survivin expression is an early event during malignant transformation, thus over expression represents a hallmark of malignancy