p53 Expression and cell proliferation in squamous cell carcinomas of the head and neck

Abstract

In squamous cell carcinoma of the head and neck (SCCHN), overexpression of the p53 protein has been found in 34-80% of the tumors studied. No data are available regarding p53 expression versus tumor cell proliferation and prognosis for this tumor type. p53 protein levels were studied by immunohistochemical staining of 33 primary SCCHN using 3 antibodies (DO7, PAb 1801, and CM1) that react with different epitopes of the p53 protein. The cellular expression of p53 was compared with in vivo incorporation of the thymidine analog iododeoxyuridine (IdUrd) and expression of proliferating cell nuclear antigen (PCNA). Twenty-one tumors (64%) had a positive nuclear staining for p53 with the monoclonal antibody DO7, which reacts with a denaturation-resistant epitope in wild-type and mutant p53. PAb 1801 and CM1 reacted with 19 and 20 tumors, respectively, all of which were DO7-positive. No correlation was found between incorporation of IdUrd and p53 expression or between PCNA and p53 expression. The data indicate that intracellular accumulation of the p53 protein was related to tumor stage and localization of the tumor. No indication of a clinical or prognostic significance of p53 expression in SCCHN was found. No association between p53 deregulation and tumor cell proliferation was found.