title: Short telomeres and ataxia-telangiectasia mutated deficiency cooperatively increase telomere dysfunction and suppress tumorigenesis.
abstract: To examine the role of ataxia-telangiectasia mutated (Atm) in telomere function, we generated Atm and telomerase null mice (Atm(-/-) mTR(-/-) iG6 mice). These mice exhibited increased germ cell death and chromosome fusions compared with either Atm(-/-) or mTR(-/-) iG6 mice. Furthermore, the Atm(-/-) mTR(--) iG6 mice had a delayed onset and reduced incidence of thymic lymphoma compared with Atm(-/-) mice. The tumors in the Atm(-/-) mTR(-/-) iG6 mice showed increased apoptosis and anaphase bridges. Finally, lymphomas from Atm(-/-) mTR(-/-) iG6 mice were derived from CD8 immature, single-positive T cells, whereas Atm(-/-) lymphomas were from CD4(+)CD8(+) double-positive T cells. We propose that Atm protects short telomeres and that Atm deficiency cooperates with short telomeres, leading to increased cell death, decreased tumorigenesis, and increased overall survival.
authors.affiliation: Departments of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Qi
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Strong
authors.forename: Baktiar O
authors.initials: BO
authors.lastname: Karim
authors.forename: Mary
authors.initials: M
authors.lastname: Armanios
authors.forename: David L
authors.initials: DL
authors.lastname: Huso
authors.forename: Carol W
authors.initials: CW
authors.lastname: Greider
mesh_terms: D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins; D016923:Cell Death / Q000235:genetics; D002471:Cell Transformation, Neoplastic; D043171:Chromosomal Instability / Q000235:genetics; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins; D005260:Female; D016399:Lymphoma, T-Cell / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency* / Q000235:genetics; D013601:T-Lymphocytes / Q000502:physiology; D019098:Telomerase / Q000172:deficiency; D016615:Telomere / Q000235:genetics / Q000502:physiology*; D025521:Tumor Suppressor Proteins
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D025521:Tumor Suppressor Proteins; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases; D019098:Telomerase