Expression of P53 and isoforms in bening and malignant lesions of the head and neck.

ABSTRACT

BACKGROUND: P53, a crucial suppressor of tumor formation, generates multiple isoforms, whose role in disease is still being defined. METHODS: By immunohistochemistry, we studied the expression of P53 protein and relative isoforms in benign papillomas (PA, n=9), inverted papilloma (IPA, n=10) and squamous cell carcinomas (SCC, n=21). RESULTS: In all lesions, P53 isoforms were significantly more expressed than P53. Immunoexpression of P53 matched with P53 isoforms in IPA as well as in SCC. Simultaneous immunoexpression of P53 and related isoforms was double in SCC compared to IPA (10% vs 24%), while expression of P53 isoforms was strongly reduced (70% vs 43%). IPA showed the highest percentage of both reactive cases and immunostained cells expressing P53 isoforms. CONCLUSIONS: We found the higher expression of P53 isoforms in IPA and SCC compared to PA, suggesting their role in local aggressiveness and malignant proliferation in head-neck lesions.