Abstract
Anaplastic large-cell lymphoma (ALCL) frequently carries the t(2;5)(p23;q35), resulting in aberrant expression of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK). We show that in 293T and Jurkat cells, forced expression of active NPM-ALK, but not kinase-dead mutant NPM-ALK (210K>R), induced JNK and cJun phosphorylation, and this was linked to a dramatic increase in AP-1 transcriptional activity. Conversely, inhibition of ALK activity in NPM-ALK(+) ALCL cells resulted in a concentration-dependent dephosphorylation of JNK and cJun and decreased AP-1 DNA-binding. In addition, JNK physically binds NPM-ALK and is highly activated in cultured and primary NPM-ALK(+) ALCL cells. cJun phosphorylation in NPM-ALK(+) ALCL cells is mediated by JNKs, as shown by selective knocking down of JNK1 and JNK2 genes using siRNA. Inhibition of JNK activity using SP600125 decreased cJun phosphorylation and AP-1 transcriptional activity and this was associated with decreased cell proliferation and G2/M cell-cycle arrest in a dose-dependent manner. Silencing of the cJun gene by siRNA led to a decreased S-phase cell-cycle fraction associated with upregulation of p21 and downregulation of cyclin D3 and cyclin A. Taken together, these findings reveal a novel function of NPM-ALK, phosphorylation and activation of JNK and cJun, which may contribute to uncontrolled cell-cycle progression and oncogenesis.
MeSH terms
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Anthracenes / pharmacology
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Anthracenes / therapeutic use
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Cell Cycle* / drug effects
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Cell Cycle* / genetics
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Cell Transformation, Neoplastic / genetics
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Cell Transformation, Neoplastic / metabolism*
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Chromosomes, Human, Pair 2 / genetics
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Chromosomes, Human, Pair 2 / metabolism
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Chromosomes, Human, Pair 5 / genetics
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Chromosomes, Human, Pair 5 / metabolism
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Cyclin A / biosynthesis
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Cyclin A / genetics
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Cyclin D3
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Cyclins / biosynthesis
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Cyclins / genetics
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Dose-Response Relationship, Drug
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Down-Regulation / drug effects
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Down-Regulation / genetics
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Enzyme Activation / drug effects
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Enzyme Activation / genetics
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Humans
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Jurkat Cells
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Lymphoma, Large B-Cell, Diffuse / drug therapy
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Lymphoma, Large B-Cell, Diffuse / enzymology*
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Lymphoma, Large B-Cell, Diffuse / genetics
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Mitogen-Activated Protein Kinase 8 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 8 / genetics
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Mitogen-Activated Protein Kinase 8 / metabolism*
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Mitogen-Activated Protein Kinase 9 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 9 / genetics
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Mitogen-Activated Protein Kinase 9 / metabolism*
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Oncogene Proteins, Fusion / genetics
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Oncogene Proteins, Fusion / metabolism*
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Phosphorylation / drug effects
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Protein Serine-Threonine Kinases / biosynthesis
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Protein Serine-Threonine Kinases / genetics
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Protein-Tyrosine Kinases / genetics
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Protein-Tyrosine Kinases / metabolism*
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Signal Transduction* / drug effects
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Signal Transduction* / genetics
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Transcription Factor AP-1 / genetics
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Transcription Factor AP-1 / metabolism
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Transcription, Genetic / drug effects
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Transcription, Genetic / genetics
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Translocation, Genetic / drug effects
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Translocation, Genetic / genetics
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Up-Regulation / drug effects
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Up-Regulation / genetics
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p21-Activated Kinases
Substances
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Anthracenes
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CCND3 protein, human
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Cyclin A
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Cyclin D3
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Cyclins
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Oncogene Proteins, Fusion
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Transcription Factor AP-1
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pyrazolanthrone
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p80(NPM-ALK) protein
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Mitogen-Activated Protein Kinase 9
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Protein-Tyrosine Kinases
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Protein Serine-Threonine Kinases
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p21-Activated Kinases
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Mitogen-Activated Protein Kinase 8