title: Expression of c-fos in cultured human nevus cells: an increase over melanocytes and melanoma cells.
abstract: Nevus cells exhibit growth characteristics in culture which differentiate them from melanocytes and melanoma cells. We examined the expression of c-jun, c-fos and jun-B mRNA levels in cultures of different melanocytic cell types to determine if biologic differences among these cells was due to their level of proto-oncogene expression. Because cell growth and differentiation are also known to be affected by serum conditions, the expression of c-jun, c-fos and jun-B was examined under normal serum conditions and serum starved and repleted conditions which stimulates proto-oncogene expression. Expression of c-jun and jun-B was not significantly different among the cell types studied under normal serum conditions, or serum starved and refed conditions and c-fos was not detectable in any of the unstimulated cell types. In contrast, when the cells were serum starved and refed, the level of c-fos expression was uniformly increased (2-10 fold) in 3 different nevus cell lines. This increase was not seen in normal melanocyte cultures or 2 melanoma cell lines. With serum deprivation and repletion, c-fos was also elevated in 1 melanoma cell line. We conclude that the regulation of the proto-oncogene c-fos is different in nevus cells than in normal melanocytes, which may contribute to the different growth characteristics seen with nevus cells.
authors.affiliation: Geriatric Research Education and Clinical Center, Department of Veterans Affairs, Salt Lake City, Utah, USA. TRALLIS@MED.UTAH.EDU
authors.forename: T M
authors.initials: TM
authors.lastname: Rallis
authors.forename: M T
authors.initials: MT
authors.lastname: Larkin
authors.forename: L A
authors.initials: LA
authors.lastname: Schmidt
authors.forename: L J
authors.initials: LJ
authors.lastname: Meyer
mesh_terms: D002478:Cells, Cultured; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism; D009508:Nevus, Pigmented / Q000235:genetics* / Q000378:metabolism*; D000090063:Proto-Oncogene Mas; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000235:genetics*; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects / Q000235:genetics; D012878:Skin Neoplasms / Q000378:metabolism
chemical_list: D016895:Culture Media, Serum-Free; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun