Activation of alpha-diacylglycerol kinase is critical for the mitogenic properties of anaplastic lymphoma kinase.
Oncogenic rearrangements of the tyrosine kinase receptor anaplastic lymphoma kinase (ALK), most commonly represented by the nucleophosmin/ALK fusion protein (NPM/ALK), are involved in the pathogenesis of anaplastic large-cell lymphomas (ALCLs). In an effort to identify new intracellular transducers operative in ALK-positive malignancies, we have investigated the potential involvement of diacylglycerol kinase (DGK). Here we show that alphaDGK is constitutively activated in the NPM/ALK-positive ALCL-derived cell line Karpas 299 and in NPM/ALK-infected 32D hematopoietic cells. These results were further validated in fibroblastic NIH-3T3 cells expressing a previously described chimeric epidermal growth factor receptor (EGFR)/ALK molecule that allows dissection of ALK enzymatic function under conditions of controlled ligand-induced activation. In this cell system, we also show that ALK-mediated alphaDGK activation is dependent on p60src tyrosine kinase, with which alphaDGK forms a complex. The specific inhibition of alphaDGK, obtained by cell treatment with R59949, significantly reduced cellular growth in all cell lines. This result was further confirmed in Karpas 299 cells following specific down-regulation of alphaDGK by RNA interference. Overall, our data indicate that alphaDGK activation is involved in the control of ALK-mediated mitogenic properties.
Bacchiocchi
Roberta
R
Laboratory of Cellular and Molecular Biology, Institute of Clinical Medicine and Applied Biotechnologies, Polytechnic University of the Marche Region, Via Tronto 10/A, 60020 Ancona, Italy.
Baldanzi
Gianluca
G
Carbonari
Damiano
D
Capomagi
Catia
C
Colombo
Emanuela
E
van Blitterswijk
Wim J
WJ
Graziani
Andrea
A
Fazioli
Francesca
F
D000077548:Anaplastic Lymphoma Kinase; D002460:Cell Line; D049109:Cell Proliferation; D019852:Diacylglycerol Kinase / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000209:etiology* / Q000473:pathology; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases; D015854:Up-Regulation
D004791:Enzyme Inhibitors; D034741:RNA, Small Interfering; C107023:p80(NPM-ALK) protein; D019852:Diacylglycerol Kinase; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)