Abstract
Intensified and central nervous system (CNS)-directed chemotherapy has improved outcomes for pediatric B cell acute lymphoblastic leukemia (B-ALL) but confers treatment-related morbidities. Moreover, many patients suffer relapses, underscoring the need to develop new molecular targeted B-ALL therapies. Using a mouse model, we show that leukemic B cells require pre-B cell receptor (pre-BCR)-independent spleen tyrosine kinase (SYK) signaling in vivo for survival and proliferation. In diagnostic samples from human pediatric and adult B-ALL patients, SYK and downstream targets were phosphorylated regardless of pre-BCR expression or genetic subtype. Two small-molecule SYK inhibitors, fostamatinib and BAY61-3606, attenuated the growth of 69 B-ALL samples in vitro, including high-risk (HR) subtypes. Orally administered fostamatinib reduced heavy disease burden after xenotransplantation of HR B-ALL samples into immunodeficient mice and decreased leukemia dissemination into spleen, liver, kidneys, and the CNS of recipient mice. Thus, SYK activation sustains the growth of multiple HR B-ALL subtypes, suggesting that SYK inhibitors may improve outcomes for HR and relapsed B-ALL.
Copyright © 2014, American Association for the Advancement of Science.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Administration, Oral
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Adult
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Aminopyridines
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Animals
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Cell Proliferation
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Cell Survival
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Child
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Female
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Humans
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Intracellular Signaling Peptides and Proteins / antagonists & inhibitors
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Intracellular Signaling Peptides and Proteins / metabolism*
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Leukemia / drug therapy
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Male
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Mice
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Mice, SCID
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Morpholines
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Mutation
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Neoplasm Transplantation
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Niacinamide / analogs & derivatives
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Niacinamide / chemistry
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Oligonucleotide Array Sequence Analysis
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Oxazines / chemistry
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Phosphorylation
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Precursor Cell Lymphoblastic Leukemia-Lymphoma / drug therapy*
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Precursor Cell Lymphoblastic Leukemia-Lymphoma / metabolism
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Precursor Cells, B-Lymphoid / cytology*
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Protein Kinase Inhibitors / chemistry*
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Protein-Tyrosine Kinases / antagonists & inhibitors
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Protein-Tyrosine Kinases / chemistry
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Protein-Tyrosine Kinases / metabolism*
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Pyridines / chemistry
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Pyrimidines / chemistry
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Recurrence
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Signal Transduction
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Spleen / enzymology*
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Syk Kinase
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Treatment Outcome
Substances
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2-(7-(3,4-dimethoxyphenyl)imidazo(1,2-c)pyrimidin-5-ylamino)nicotinamide
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Aminopyridines
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Intracellular Signaling Peptides and Proteins
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Morpholines
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Oxazines
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Protein Kinase Inhibitors
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Pyridines
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Pyrimidines
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Niacinamide
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Protein-Tyrosine Kinases
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SYK protein, human
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Syk Kinase
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Syk protein, mouse
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fostamatinib