Abstract
The Ras pathway transduces divergent signals determining normal cell fate and is frequently activated in hematopoietic malignancies, but the manner in which activation contributes to human leukemia is poorly understood. We report that a high level of activated H-Ras signaling in transduced primary human hematopoietic progenitors reduced their proliferation and enhanced monocyte/macrophage differentiation. However, the exposure of these cells to a farnesyltransferase inhibitor and establishment of a moderate level of Ras activity showed increased proliferation, an elevated frequency of primitive blast-like cells, and progenitors with enhanced self-renewal capacity. These results suggest that the amplitude of Ras pathway signaling is a determinant of myeloid cell fate and that moderate Ras activation in primitive hematopoietic cells can be an early event in leukemogenesis.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alkyl and Aryl Transferases / antagonists & inhibitors*
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Alkyl and Aryl Transferases / metabolism
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Animals
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Cell Differentiation / physiology
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Cell Division / physiology
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Cell Lineage
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Cells, Cultured
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Enzyme Activation
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Enzyme Inhibitors / metabolism
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Farnesyltranstransferase
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Gene Transfer Techniques
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Genes, ras
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Hematopoietic Stem Cells / physiology*
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Humans
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Leukemia / metabolism*
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Leukemia / physiopathology
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Mitogen-Activated Protein Kinases / antagonists & inhibitors
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Mitogen-Activated Protein Kinases / metabolism
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Organic Chemicals / metabolism
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Phosphatidylinositol 3-Kinases / metabolism
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Phosphoinositide-3 Kinase Inhibitors
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Signal Transduction / physiology*
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p38 Mitogen-Activated Protein Kinases
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ras Proteins / genetics
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ras Proteins / metabolism*
Substances
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Enzyme Inhibitors
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Organic Chemicals
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Phosphoinositide-3 Kinase Inhibitors
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SCH 66177
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Alkyl and Aryl Transferases
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Farnesyltranstransferase
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Mitogen-Activated Protein Kinases
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p38 Mitogen-Activated Protein Kinases
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ras Proteins