title: Myc-mediated proliferation and lymphomagenesis, but not apoptosis, are compromised by E2f1 loss.
abstract: Myc and E2f1 promote cell cycle progression, but overexpression of either can trigger p53-dependent apoptosis. Mice expressing an Emu-Myc transgene in B lymphocytes develop lymphomas, the majority of which sustain mutations of either the Arf or p53 tumor suppressors. Emu-Myc transgenic mice lacking one or both E2f1 alleles exhibited a slower onset of lymphoma development associated with increased expression of the cyclin-dependent kinase inhibitor p27(Kip1) and a reduced S phase fraction in precancerous B cells. In contrast, Myc-induced apoptosis and the frequency of Arf and p53 mutations in lymphomas were unaffected by E2f1 loss. Therefore, Myc does not require E2f1 to induce Arf, p53, or apoptosis in B cells, but depends upon E2f1 to accelerate cell cycle progression and downregulate p27(Kip1).
authors.affiliation: Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
authors.forename: Troy A
authors.initials: TA
authors.lastname: Baudino
authors.forename: Kirsteen H
authors.initials: KH
authors.lastname: Maclean
authors.forename: Jennifer
authors.initials: J
authors.lastname: Brennan
authors.forename: Evan
authors.initials: E
authors.lastname: Parganas
authors.forename: Chunying
authors.initials: C
authors.lastname: Yang
authors.forename: Aaron
authors.initials: A
authors.lastname: Aslanian
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Lees
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Sherr
authors.forename: Martine F
authors.initials: MF
authors.lastname: Roussel
authors.forename: John L
authors.initials: JL
authors.lastname: Cleveland
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics*; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D005260:Female; D005838:Genotype; D008223:Lymphoma / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D016196:S Phase / Q000235:genetics; D014157:Transcription Factors / Q000172:deficiency* / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C493961:Cdkn1b protein, mouse; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493754:E2f1 protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D020823:ADP-Ribosylation Factor 1