Abstract: Objective To investigate expression of p63、PCNA and epidermal growth factor receptor(EGFr)in skin squamous cell carcinoma(SCC).Method Tissue specimens from 68 cases of SCC were studied using immunohistochemistry staining method with monoclonal antibodies to p63、PCNA and EGFr. Results The expression of p63 protein and PCNA was principally restricted to basal cells with high proliferative potentiality and was absent in cells of stratum corneum that were undergoing terminal differentiation in normal or carcinoma epidermis. In highly differentiated tumors, the staining of p63 formed a ring surrounding carcinoma nests. In low differentiated tumors, p63 positive cells were increased and disorderly arranged. Diffuse expression of PCNA and EGFr was found through out all carcinoma nests. Expression of p63、PCNA and EGFr was significantly stronger in SCC and intraepithelial neoplasm(SIN)level Ⅲthan those in normal or proliferative epidermis near the carcinoma. A significant correlation was found between expression of p63,PCNA,EGFr and degree of differentiation of SCC,and between p63 and EGFr,p63 and PCNA,PCNA and EGFr, respectively. Conclusion Overexpression of p63、PCNA?EGFr may be contributed to acquisition of enhanced capability of proliferation, aggression and anaplasia in SCC.

Key words: Carcinoma,skin squamous cell, p63, Proliferating cell nuclear antigen, Receptors,epidermal growth factor urogastrone