Nucleophosmin-anaplastic lymphoma kinase associated with anaplastic large-cell lymphoma activates the phosphatidylinositol 3-kinase/Akt antiapoptotic signaling pathway.
More than half of anaplastic large-cell lymphomas (ALCLs) have a chromosomal translocation t(2;5) that leads to the expression of a hybrid protein composed of the nucleolar phosphoprotein nucleophosmin (NPM) and the anaplastic lymphoma kinase (ALK) that exhibits an unregulated tyrosine kinase activity. We have previously identified PLC-gamma as a crucial downstream signaling molecule of NPM-ALK that contributes to its mitogenic potential. Here, we show that NPM-ALK recruits the C-terminal SH2 domain of the phosphatidylinositol 3-kinase (PI 3kinase) p85 subunit. PI 3-kinase assays revealed that the kinase is activated by NPM-ALK in vivo, in turn activating PKB/Akt in NPM-ALK-expressing cells. The use of 2 specific PI 3-kinase inhibitors, wortmannin and LY294002, demonstrated the requirement of PI 3-kinase for the growth of NPM-ALK-transformed cell lines, as well as a cell line established from a patient with ALCL. Primary murine bone marrow retrovirally transduced with NPM-ALK showed a transformed phenotype that was reversible on treatment with PI 3-kinase inhibitors. Flow cytometric analysis revealed that wortmannin-treated NPM-ALK-transformed cell lines underwent apoptosis. Furthermore, apoptosis induced by overexpression of the proapoptotic molecule Bad could be partially blocked by the overexpression of NPM-ALK. Thus, NPM-ALK activates the antiapoptotic PI 3-kinase/Akt pathway, which likely contributes to the molecular pathogenesis of ALCL. (Blood. 2000;96:4319-4327)
Bai
R Y
RY
Department of Internal Medicine III, Laboratory of Leukemogenesis, Technical University of Munich, Germany.
Ouyang
T
T
Miething
C
C
Morris
S W
SW
Peschel
C
C
Duyster
J
J
D019943:Amino Acid Substitution; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001665:Binding Sites; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000502:physiology; D002461:Cell Line, Transformed / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D002470:Cell Survival / Q000502:physiology*; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D002867:Chromones / Q000494:pharmacology; D018920:Coculture Techniques; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009025:Morpholines / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D017354:Point Mutation; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases; D021122:Protein Subunits; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D017154:Stromal Cells; D014162:Transfection; D000077191:Wortmannin; D051025:bcl-Associated Death Protein; D018909:src Homology Domains
D000730:Androstadienes; D002352:Carrier Proteins; D002867:Chromones; D004791:Enzyme Inhibitors; D007377:Interleukin-3; D009025:Morpholines; D009363:Neoplasm Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D021122:Protein Subunits; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011993:Recombinant Fusion Proteins; D000077191:Wortmannin; D051025:bcl-Associated Death Protein; C494819:BAD protein, human; C494820:Bad protein, mouse; C494821:Bad protein, rat; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C107023:p80(NPM-ALK) protein; C494918:AKT1 protein, human; C494920:Akt1 protein, rat