Discovering early molecular determinants of leukemogenesis.

Department of Medicine and Molecular and Medical Genetics, Oregon Health and Sciences University, Oregon, USA.
Journal of Clinical Investigation (Impact Factor: 12.81). 04/2008; 118(3):847-50. DOI: 10.1172/JCI35109
Source: PubMed

ABSTRACT Truncating mutations of the G-CSF receptor are found during disease course in nearly half of all patients with severe congenital neutropenia. In this issue of the JCI, Liu et al. demonstrate that these mutations confer a competitive clonal advantage upon HSCs in mice and that the advantage is conditional because it is observed only in the presence of the ligand G-CSF (see the related article beginning on page 946). Once activated, the mutant receptor requires the function of Stat5 in order to effect clonal expansion of this stem cell population. The results support the notion that early molecular steps in this and other neoplastic processes represent adaptations in which, through somatic mutations, "unfit" stem cells gain a measure of fitness by altering their relationships with their microenvironment.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Congenital Neutropenia (CN) is a heterogeneous bone marrow failure syndrome characterized by a maturation arrest of myelopoiesis at the level of the promyelocyte/myelocyte stage with peripheral blood absolute neutrophil counts below 0.5 x 10(9)/l. There are two major subtypes of CN as judged by inheritance: an autosomal dominant subtype, e.g. defined by neutrophil elastase mutations (approximately 60% of patients) and an autosomal recessive subtype (approximately 30% of patients), both presenting with the same clinical and morphological phenotype. Different mutations have been described (e.g. HAX1, p14 etc) in autosomal recessive CN, with HAX1 mutations in the majority of these patients. CN in common is considered as a preleukemic syndrome, since the cumulative incidence for leukemia is more than 25% after 20 years of observation. Leukemias occur in both, the autosomal dominant and recessive subtypes of CN. The individual risk for each genetic subtype needs to be further evaluated. Numbers of patients tested for the underlying genetic defect are still limited. Acquired G-CSFR (CSF3R) mutations are detected in approximately 80% of CN patients who developed acute myeloid leukemia independent of the ELA2 or HAX1 genetic subtype, suggesting that these mutations are involved in leukemogenesis. As the majority of patients benefit from G-CSF administration, HSCT should be restricted to non-responders and patients with leukaemic transformation.
    British Journal of Haematology 01/2009; 144(4):459-67. · 4.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Severe congenital neutropenia (CN) is a rare bone marrow failure syndrome with a high incidence of acute leukemia. In previous studies, we could show that point mutations in the gene for the granulocyte colony-stimulating factor (G-CSF) receptor CSF3R are a highly predictive marker for leukemic development in CN patients. To find out at which stage of hematopoietic development these mutations emerge and how they are propagated during hematopoietic differentiation, we analyzed single cells of different hematopoietic subpopulations from CN patients with CSF3R mutations. We found that CSF3R mutations are not restricted to the myeloid compartment but are also detectable in lymphoid cells, although at a much lower percentage. From our observations, we conclude that CSF3R mutations are acquired in multipotent hematopoietic progenitor cells in CN patients and that they are clonally expanded in myeloid cells expressing the G-CSF receptor due to the growth advantage mediated by the CSF3R mutation.
    Blood 12/2008; 113(3):668-70. · 9.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aplastic anemia (AA) and myelodysplastic syndromes (MDS) are a heterogeneous group of rare hematological disorders belonging to the Bone Marrow Failure (BMF) syndromes. The Aplastic Anemia and Myelodysplastic Syndromes International Foundation (AA&MDSIF) is a non-profit organization dedicated to supporting patients and families living with a BMF disease. They work to bring investigators together in a collaborative manner. This article summarizes key presentations from the last AA&MDSIF scientific symposium held in Bethesda, Maryland on March 2010.
    Leukemia research 10/2010; 35(3):291-4. · 2.36 Impact Factor


Available from