LOCALIZATION OF P53 PROTEIN AND HUMAN-PAPILLOMAVIRUS IN LARYNGEAL SQUAMOUS LESIONS

The p53 tumour suppressor protein can be ineffective because of mutati ons in the p53 gene or interactions with proteins synthesized by speci fic subtypes of HPV. We investigated the localization of p53 protein i n association with HPV in paraffin sections of 10 dysplastic and 12 ma lignant laryngeal squamous epithelium specimens by using immunohistoch emical and in situ hybridization techniques. Viral HPV type 16 or 18 r elated sequences were identified only in a squamous cell carcinoma (SC C) specimen. p53 was detected in 64% of cases studied. All p53+ specim ens showed no HPV related sequences; the only HPV+ case was p53 negati ve. In our study, the increased p53 expression in the process from dys plastic to invasive SCC indicates that p53 overexpression is an early event in laryngeal carcinogenesis. Moreover, the systemic susceptibili ty to HPV infection suggests the need for an accurate evaluation of SC C risk not only in the genital tract in female patients shown to be po sitive for transforming HPV types (16 or 18).