CELL-SURFACE EXPRESSION OF 70 KDA HEAT-SHOCK-PROTEIN IN HUMAN ORAL DYSPLASIA AND SQUAMOUS-CELL CARCINOMA - CORRELATION WITH CLINICOPATHOLOGICAL FEATURES

To understand the role of 70 kDa heat shock protein (HSP70) in the pat hogenesis of oral cancer, its expression was studied in human normal, premalignant and malignant oral mucosa. Cell surface expression of HSP 70 was assessed in oral tissue specimens by flow cytometric analysis u sing a mouse monoclonal antibody against HSP70. A significant increase in cell surface expression of HSP70 was observed as the tissue progre ssed from normal to dysplasia towards carcinoma. Correlation of HSP70 expression with clinicopathological features showed a positive associa tion with the severity of dysplasia. Among the oral tumours assessed, a significantly positive association was observed between HSP70 expres sion and dedifferentiation of oral squamous cell carcinomas (SCCs). Po orly differentiated tumours showed significantly higher levels of HSP7 0 expression on the surface of tumour cells, compared with well differ entiated carcinomas (P < 0.05). Cell surface expression of HSP70 was o bserved to be significantly higher in clinically advanced stage tumour s (T-3/T-4), compared with T-1/T-2 stage tumours (P < 0.05). The Varia tion in cell surface expression of HSP70 in normal, dysplastic and mal ignant oral lesions suggests that it is differentially expressed durin g oral tumorigenesis and may play a specific role in the pathogenesis of oral cancer. (C) 1998 Elsevier Science Ltd. All rights reserved.