Walters, D. K. et al. Activating alleles of JAK3 in acute megakaryoblastic leukemia. Cancer Cell 10, 65-75

Howard Hughes Medical Institute, Portland, Oregon 97239, USA.
Cancer Cell (Impact Factor: 23.52). 08/2006; 10(1):65-75. DOI: 10.1016/j.ccr.2006.06.002
Source: PubMed


Tyrosine kinases are aberrantly activated in numerous malignancies, including acute myeloid leukemia (AML). To identify tyrosine kinases activated in AML, we developed a screening strategy that rapidly identifies tyrosine-phosphorylated proteins using mass spectrometry. This allowed the identification of an activating mutation (A572V) in the JAK3 pseudokinase domain in the acute megakaryoblastic leukemia (AMKL) cell line CMK. Subsequent analysis identified two additional JAK3 alleles, V722I and P132T, in AMKL patients. JAK3(A572V), JAK3(V722I), and JAK3(P132T) each transform Ba/F3 cells to factor-independent growth, and JAK3(A572V) confers features of megakaryoblastic leukemia in a murine model. These findings illustrate the biological importance of gain-of-function JAK3 mutations in leukemogenesis and demonstrate the utility of proteomic approaches to identifying clinically relevant mutations.

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Available from: Michael C Heinrich, Oct 10, 2015
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    • "Cell viability was assessed using the CellTiter 96 Aqueous One Solution Cell Proliferation (MTS) Assay (Promega, Madison, WI), as described [28]. Cells suspended in supplemented EGM-2 medium were seeded in 96-well microtiter plates at a density of 2500 to 10,000 cells per well and allowed to adhere overnight, at which time various concentrations of the inhibitors were added. "
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    ABSTRACT: Hemangiosarcoma, a natural model of human angiosarcoma, is an aggressive vascular tumor diagnosed commonly in dogs. The documented expression of several receptor tyrosine kinases (RTKs) by these tumors makes them attractive targets for therapeutic intervention using tyrosine kinase inhibitors (TKIs). However, we possess limited knowledge of the effects of TKIs on hemangiosarcoma as well as other soft tissue sarcomas. We report here on the use of the TKIs imatinib and dasatinib in canine hemangiosarcoma and their effects on platelet-derived growth factor receptor β (PDGFR-β) and Src inhibition. Both TKIs reduced cell viability, but dasatinib was markedly more potent in this regard, mediating cytotoxic effects orders of magnitude greater than imatinib. Dasatinib also inhibited the phosphorylation of the shared PDGFR-β target at a concentration approximately 1000 times less than that needed by imatinib and effectively blocked Src phosphorylation. Both inhibitors augmented the response to doxorubicin, suggesting that clinical responses likely will be improved using both drugs in combination; however, dasatinib was significantly (P < .05) more effective in this context. Despite the higher concentrations needed in cell-based assays, imatinib significantly inhibited tumor growth (P < .05) in a tumor xenograft model, highlighting that disruption of PDGFR-β/PDGF signaling may be important in targeting the angiogenic nature of these tumors. Treatment of a dog with spontaneously occurring hemangiosarcoma established that clinically achievable doses of dasatinib may be realized in dogs and provides a means to investigate the effect of TKIs on soft tissue sarcomas in a large animal model.
    Translational oncology 04/2013; 6(2):158-68. DOI:10.1593/tlo.12307 · 2.88 Impact Factor
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    • "genetic alterations might be necessary for progression from TAM to AMKL (Ahmed et al, 2004). Although acquired mutations of TP53, JAK3, JAK2 or FLT3 have been found in patients with DS-AMKL, the incidence of those gene mutations was low, and TP53 and JAK3 gene mutations have been identified in both DS-AMKL and TAM (Malkin et al, 2000; Walters et al, 2006; De Vita et al, 2007; Kiyoi et al, 2007; Klusmann et al, 2007; Malinge et al, 2008). Mutations of GATA1, JAK2, FLT3, KIT, or MPL were also found in children with non-DS-AMKL (Malinge et al, 2008). "
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    ABSTRACT: While acute megakaryoblastic leukaemia (AMKL) occurs in children with (DS-AMKL) and without (paediatric non-DS-AMKL) Down syndrome, it can also affect adults without DS (adult non-DS-AMKL). We have analysed these subgroups of patients (11 children with DS-AMKL, 12 children and four adults with non-DS-AMKL) for the presence of molecular lesions, including mutations and chromosomal abnormalities studied by sequencing and single nucleotide polymorphism array-based karyotyping, respectively. In children, AMKL was associated with trisomy 21 (somatic in non-DS-AMKL), while numerical aberrations of chromosome 21 were only rarely associated with adult AMKL. DS-AMKL was also associated with recurrent somatic gains of 1q (4/11 DS-AMKL patients). In contrast to trisomy 21 and gains of 1q, other additional chromosomal lesions were evenly distributed between children and adults with AMKL. A mutational screen found GATA1 mutations in 11/12 DS-AMKL, but mutations were rare in paediatric non-DS-AMKL (1/12) and adult AMKL (0/4). JAK3 (1/11), JAK2 (1/11), and TP53 mutations (1/11) were found only in patients with DS-AMKL. ASXL1, IDH1/2, DNMT3A, RUNX1 and CBL mutations were not found in any of the patient group studied, while NRAS mutation was identified in two patients with paediatric non-DS-AMKL.
    British Journal of Haematology 11/2011; 156(3):316-25. DOI:10.1111/j.1365-2141.2011.08948.x · 4.71 Impact Factor
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    • "Studies have also shown that the JAKs interact with other well-known mitogenic pathways such as Raf/MEK signaling in the pathogenesis of malignancies [17,18]. Nevertheless, most JAK3 studies focused on leukemias, immune related diseases and lymphomas [11,19] and a relatively small number of studies were performed in solid cancer [16,20]. Recently, it has been suggested that the JAK-STAT pathway may be an effective target to control abnormal cell proliferation in lung cancer or pulmonary fibrosis through neuregulin-1 activation [21]. "
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    ABSTRACT: The genetic alteration of the janus kinases (JAKs), non-receptor tyrosine kinase, is related to the development of human cancers. However, little is known about how the sequence variation of JAK3 contributes to the development of lung cancer. This study investigated whether polymorphisms at the promoter region of the JAK3 gene are associated with the risk of lung cancer in the Korean population. A total of 819 subjects, including 409 lung cancer patients and 410 healthy controls were recruited. The SNaPshot assay and polymerase chain reaction-restriction fragment length polymorphism analysis were used, and logistic regression analyses were performed to characterize the association between polymorphisms of JAK3 and lung cancer risk. Three polymorphisms (-672 G>A, +64 A>G and +227 G>A) of JAK3 were analyzed for large-scale genotyping (n=819). Statistical analyses revealed that polymorphisms and haplotypes in the JAK3 gene were not significantly associated with lung cancer. JAK3 gene was not significantly associated with the risk of lung cancer in the Korean population.
    Cancer Research and Treatment 06/2011; 43(2):108-16. DOI:10.4143/crt.2011.43.2.108 · 3.32 Impact Factor
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