p53, p63 and p73 expression in squamous cell carcinomas of the head and neck and their response to cisplatin exposure.

p63 and p73 share significant structural and functional homologies with the tumour suppressor p53. Unlike the p53 gene, both encode for several isoforms which vary in their NH2 and COOH termini with variable and, in part, opposed biological functions. The objective of the present study was to analyse the expression profiles of p53 family members in squamous cell carcinomas of the head and neck (HNSCC) and their alterations caused by exposure to the clinically active drug cisplatin. Using multiplex RT-PCR combined with the Southern technique, we determined transcription of p53 family members in 10 established HNSCC cell lines. In the majority of HNSCC, p53 and different p63/p73 isoforms were expressed with cell-line-specific patterns for composition and intensity of transcript expression. Exposure to cisplatin caused multiple alterations in the p63 and p73 profiles suggesting a complex regulation which may influence the sensitivity to chemotherapy.