title: Oncogenic Kras initiates leukemia in hematopoietic stem cells.
abstract: How oncogenes modulate the self-renewal properties of cancer-initiating cells is incompletely understood. Activating KRAS and NRAS mutations are among the most common oncogenic lesions detected in human cancer, and occur in myeloproliferative disorders (MPDs) and leukemias. We investigated the effects of expressing oncogenic Kras(G12D) from its endogenous locus on the proliferation and tumor-initiating properties of murine hematopoietic stem and progenitor cells. MPD could be initiated by Kras(G12D) expression in a highly restricted population enriched for hematopoietic stem cells (HSCs), but not in common myeloid progenitors. Kras(G12D) HSCs demonstrated a marked in vivo competitive advantage over wild-type cells. Kras(G12D) expression also increased the fraction of proliferating HSCs and reduced the overall size of this compartment. Transplanted Kras(G12D) HSCs efficiently initiated acute T-lineage leukemia/lymphoma, which was associated with secondary Notch1 mutations in thymocytes. We conclude that MPD-initiating activity is restricted to the HSC compartment in Kras(G12D) mice, and that distinct self-renewing populations with cooperating mutations emerge during cancer progression.
authors.affiliation: Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Amit J
authors.initials: AJ
authors.lastname: Sabnis
authors.forename: Laurene S
authors.initials: LS
authors.lastname: Cheung
authors.forename: Monique
authors.initials: M
authors.lastname: Dail
authors.forename: Hio Chung
authors.initials: HC
authors.lastname: Kang
authors.forename: Marianne
authors.initials: M
authors.lastname: Santaguida
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Hermiston
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Passegué
authors.forename: Kevin
authors.initials: K
authors.lastname: Shannon
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Braun
mesh_terms: D000818:Animals; D001483:Base Sequence; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology*; D007942:Leukemia, Experimental / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009196:Myeloproliferative Disorders / Q000378:metabolism / Q000473:pathology; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism / Q000473:pathology*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology
chemical_list: C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)