title: Hormonal modulation of c-fos expression in isolated hepatocytes. Effects of angiotensin II and phorbol myristate acetate on transcription and mRNA degradation.
abstract: It has been shown that angiotensin II and PMA increase the expression of proto-oncogenes (c-fos, c-myc and c-mos) in liver cells. In this study the effects of angiotensin II and PMA on c-fos transcription and mRNA stability were investigated. Using nuclear run-off transcription assays, it was observed that PMA and angiotensin II induced a rapid increase in c-fos transcription. The transcription rate of the GAPDH gene did not change, indicating that the effects were not general on gene transcription. The ability of these agents to modulate proto-oncogene mRNA stability was tested by measuring c-fos mRNA half-life. It was observed that c-fos mRNA half-life was relatively short (approximately 14-18 min) and that angiotensin II and PMA markedly stabilized mRNA, increasing its half-life (approximately 4-fold and approximately 2-fold, respectively). The protein synthesis inhibitor cycloheximide increased mRNA stability to a much greater extent. Our results clearly demonstrate that angiotensin II and PMA increased c-fos mRNA accumulation in liver cells through two actions: induction of c-fos gene transcription and increase in mRNA stability.
authors.affiliation: Departmento de Bioenergética, Instituto de fisiología Celular, Universidad Nacional Autónoma de México.
authors.forename: C
authors.initials: C
authors.lastname: González-Espinosa
authors.forename: J A
authors.initials: JA
authors.lastname: García-Sáinz
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D005260:Female; D005786:Gene Expression Regulation; D016762:Genes, fos; D008099:Liver / Q000166:cytology / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D000804:Angiotensin II; D013755:Tetradecanoylphorbol Acetate