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

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 immune-expression 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.