OVEREXPRESSION OF EGF RECEPTOR IS ASSOCIATED WITH SPONTANEOUS METASTASES OF A HUMAN-MELANOMA CELL-LINE IN NUDE-MICE

Twelve human melanoma cell lines were analyzed for alterations in the epidermal growth factor receptor (EGFR) gene at the DNA, RNA, and prot ein levels. EGFR expression of the cell lines was then correlated with their previously reported p53 expression, in vivo growth characterist ics, and rate of metastases in athymic mice. Northern blot and immunoc ytochemical analyses demonstrated low to intermediate levels of EGF re ceptor expression in four cell lines. Overexpression of EGFR was seen in one cell line, UISO-MEL-6. Although no significant statistical diff erence was observed between in vivo growth of EGFR-positive cell lines versus EGFR-negative cell lines, UISO-MEL-6 which also lacked p53 exp ression, had the fastest in vivo rate of growth and was the only cell line to produce visceral metastases following subcutaneous inoculation in nude mice. Furthermore, EGFR overexpression in UISO-MEL-6 was asso ciated with alterations of the gene at the DNA level.