title: Reversible activation of c-Myc in thymocytes enhances positive selection and induces proliferation and apoptosis in vitro.
abstract: In order to study the effect of c-Myc activation in T lymphocytes in vivo, we generated transgenic mice that express a 4-hydroxytamoxifen (4-OHT)-dependent switchable c-myc oncoprotein under the control of the proximal lck promoter. Activation of c-MycER causes no obvious alteration in T cell ontogeny. However, using MHC class I restricted H-Y-TCR transgenic mice, we found that c-Myc activation in vivo enhances the efficiency of positive selection. Moreover, splenic T cells derived from lck-c-mycER transgenic mice in which c-Myc had been activated exhibited increased proliferation in vitro in response to activation with anti-CD3/CD28 antibody. Activation of c-MycER also promotes apoptosis in thymocytes in vitro.
authors.affiliation: Imperial Cancer Research Fund, PO Box 123, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
authors.forename: B
authors.initials: B
authors.lastname: Rudolph
authors.forename: A O
authors.initials: AO
authors.lastname: Hueber
authors.forename: G I
authors.initials: GI
authors.lastname: Evan
mesh_terms: D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D002455:Cell Division; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc; D051379:Mice; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000378:metabolism* / Q000502:physiology; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology; D013950:Thymus Gland / Q000166:cytology
chemical_list: D013629:Tamoxifen; C016601:afimoxifene