ANALYSIS OF P53 IN HUMAN CUTANEOUS MELANOMA CELL-LINES

Mutations in the p53 tumour suppressor gene have been detected in a va riety of human malignancies. Mutations have been found predominantly i n conserved regions two to five. Our aim was to analyse p53 at the pro tein and DNA level in seven melanoma cell lines of cutaneous origin (H MB-2, DX3, LT5.1, MJM, SK23, A375P and A375M), including two parental/ metastatic derivatives (A375P and A375M; DX3 and LT5.1). By immunohist ochemical staining with three mouse monoclonal antibodies and a rabbit polyclonal serum, it was possible to observe differential nuclear exp ression of p53. The quantitation of p53 protein levels by ELISA correl ated with the nuclear staining pattern. Western blotting showed an int act p53 protein in all cell lines; p53 was polymorphic in three cell l ines (MJM, A375P and A375M). DNA sequencing studies showed that all ce ll lines had wild type p53. These results suggest that p53 is unlikely to play a significant role in the genesis of cutaneous melanoma.