title: Differential induction of 15 and 16 kDa nuclear proteins in promotion sensitive and promotion resistant mouse JB6 cells.
abstract: Gene expression relevant to promotion of neoplastic transformation was investigated by measuring proteins differentially synthesized in two mouse epidermal JB6 cell lines sensitive (P+) or resistant (P-) to tumor promoter induced transformation. One dimensional polyacrylamide gel electrophoresis of proteins from cells that had been pulse labeled with 35S-methionine after various times of exposure to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) revealed two protein bands whose intensity increased after 20-24 hr exposure to TPA. Cell fractionation showed that these proteins of 15 and 16 kDa were localized in the nuclear, not the cytosolic, fraction. Parallel studies with 32P-labeled cells showed no evidence for phosphorylation of these proteins. Comparison of P- with P+ cells showed that the observed induction of p15/16 synthesis at 20 hr was specific for P+ cells, with little evidence for stimulated synthesis in P- cells during a 48 hr period. We thus conclude that the tumor promoter produces a late stimulation in the rate of synthesis of 15 and 16 kDa nuclear proteins preferentially in promotion sensitive cells.
authors.affiliation: Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick Cancer Research and Development Center, MD 21702-1201.
authors.forename: K
authors.initials: K
authors.lastname: Hirano
authors.forename: B M
authors.initials: BM
authors.lastname: Smith
authors.forename: N H
authors.initials: NH
authors.lastname: Colburn
mesh_terms: D000818:Animals; D002273:Carcinogens; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D051379:Mice; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D002273:Carcinogens; D009687:Nuclear Proteins; D013755:Tetradecanoylphorbol Acetate