title: Drug-induced reversion of progression phenotype is accompanied by reversion of AP-1 phenotype in JB6 cells.
abstract: Transformed JB6 cells can be stably reverted to nontransformed phenotype by AP-1 inhibiting gluccorticoid fluocinolone (FA) and cAMP elevator forskolin (FN), yielding stable revertants of promotion resistant (P-) and promotion sensitive (P+) phenotypes. AP-1 activity of nontransformed P- and P+ revertant clones was decreased under a variety of experimental conditions compared with their transformed counterparts. Moreover, AP-1 activity in P+ cells under anchorage-independent conditions was induced by 12-0-tetradecanoyl-phorbol-13-acetate (TPA) while AP-1 activity in the reverted P- cells was not induced, just as observed for the original P+ and P- variants. Taken together these data suggest that changes in AP-1 activity may be one key mediator not only of forward progression but also of reversion of tumor cells to nontransformed phenotype. In addition, the higher transfection efficiency of the new reverted P- and P+ cells renders them useful for studying the role of transcription factors in tumor promotion.
authors.affiliation: Laboratory of Viral Carcinogenesis, NCI-FCRDC, Frederick, Maryland 21702-1201, USA.
authors.forename: V
authors.initials: V
authors.lastname: Lavrovsky
authors.forename: Z
authors.initials: Z
authors.lastname: Dong
authors.forename: W Y
authors.initials: WY
authors.lastname: Ma
authors.forename: N
authors.initials: N
authors.lastname: Colburn
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D002999:Clone Cells / Q000187:drug effects; D005576:Colforsin / Q000494:pharmacology*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005446:Fluocinolone Acetonide / Q000494:pharmacology*; D005938:Glucocorticoids / Q000494:pharmacology*; D051379:Mice; D010641:Phenotype; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014162:Transfection
chemical_list: D005938:Glucocorticoids; D018808:Transcription Factor AP-1; D005446:Fluocinolone Acetonide; D005576:Colforsin; D004815:Epidermal Growth Factor; D013755:Tetradecanoylphorbol Acetate