| 1. |
- Angenendt, Linus, et al.
(författare)
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Chromosomal Abnormalities and Prognosis in NPM1-Mutated Acute Myeloid Leukemia : A Pooled Analysis of Individual Patient Data From Nine International Cohorts
- 2019
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Ingår i: Journal of Clinical Oncology. - : AMER SOC CLINICAL ONCOLOGY. - 0732-183X .- 1527-7755. ; 37:29, s. 2632-2642
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Nucleophosmin 1 (NPM1) mutations are associated with a favorable prognosis in acute myeloid leukemia (AML) when an internal tandem duplication (ITD) in the fms-related tyrosine kinase 3 gene (FLT3) is absent (FLT3-ITDneg) or present with a low allelic ratio (FLT3-ITDlow). The 2017 European LeukemiaNet guidelines assume this is true regardless of accompanying cytogenetic abnormalities. We investigated the validity of this assumption.METHODS: We analyzed associations between karyotype and outcome in intensively treated patients with NPM1(mut)/FLT3-ITDneg/low AML who were prospectively enrolled in registry databases from nine international study groups or treatment centers.RESULTS: Among 2,426 patients with NPM1(mut)/FLT3-ITDneg/low AML, 2,000 (82.4%) had a normal and 426 (17.6%) had an abnormal karyotype, including 329 patients (13.6%) with intermediate and 83 patients (3.4%) with adverse-risk chromosomal abnormalities. In patients with NPM1(mut)/FLT3-ITDneg/low AML, adverse cytogenetics were associated with lower complete remission rates (87.7%, 86.0%, and 66.3% for normal, aberrant intermediate, and adverse karyotype, respectively; P < .001), inferior 5-year overall (52.4%, 44.8%, 19.5%, respectively; P < .001) and event-free survival (40.6%, 36.0%, 18.1%, respectively; P < .001), and a higher 5-year cumulative incidence of relapse (43.6%, 44.2%, 51.9%, respectively; P = .0012). These associations remained in multivariable mixed-effects regression analyses adjusted for known clinicopathologic risk factors (P < .001 for all end points). In patients with adverse-risk chromosomal aberrations, we found no significant influence of the NPM1 mutational status on outcome.CONCLUSION: Karyotype abnormalities are significantly associated with outcome in NPM1(mut)/FLT3-ITDneg/low AML. When adverse-risk cytogenetics are present, patients with NPM1(mut) share the same unfavorable prognosis as patients with NPM1 wild type and should be classified and treated accordingly. Thus, cytogenetic risk predominates over molecular risk in NPM1(mut)/FLT3-ITDneg/low AML.
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| 2. |
- Behrens, Kira, et al.
(författare)
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RUNX1 cooperates with FLT3-ITD to induce leukemia
- 2017
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Ingår i: Journal of Experimental Medicine. - : ROCKEFELLER UNIV PRESS. - 0022-1007 .- 1540-9538. ; 214:3, s. 737-752
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Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is induced by the cooperative action of deregulated genes that perturb self-renewal, proliferation, and differentiation. Internal tandem duplications (ITDs) in the FLT3 receptor tyrosine kinase are common mutations in AML, confer poor prognosis, and stimulate myeloproliferation. AML patient samples with FLT3-ITD express high levels of RUNX1, a transcription factor with known tumor-suppressor function. In this study, to understand this paradox, we investigated the impact of RUNX1 and FLT3-ITD coexpression. FLT3-ITD directly impacts on RUNX1 activity, whereby up-regulated and phosphorylated RUNX1 cooperates with FLT3-ITD to induce AML. Inactivating RUNX1 in tumors releases the differentiation block and down-regulates genes controlling ribosome biogenesis. We identified Hhex as a direct target of RUNX1 and FLT3-ITD stimulation and confirmed high HHEX expression in FLT3-ITD AMLs. HHEX could replace RUNX1 in cooperating with FLT3-ITD to induce AML. These results establish and elucidate the unanticipated oncogenic function of RUNX1 in AML. We predict that blocking RUNX1 activity will greatly enhance current therapeutic approaches using FLT3 inhibitors.
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| 3. |
- Hehlmann, Ruediger, et al.
(författare)
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The European LeukemiaNet : achievements and perspectives
- 2011
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 96:1, s. 156-162
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Tidskriftsartikel (refereegranskat)abstract
- The only way to cure leukemia is by cooperative research. To optimize research, the European Leukemia Net integrates 105 national leukemia trial groups and networks, 105 interdisciplinary partner groups and about 1,000 leukemia specialists from 175 institutions. They care for tens of thousands of leukemia patients in 33 countries across Europe. Their ultimate goal is to cure leukemia. Since its inception in 2002, the European Leukemia Net has steadily expanded and has unified leukemia research across Europe. The European Leukemia Net grew from two major roots: 1) the German Competence Network on Acute and Chronic Leukemias; and 2) the collaboration of European Investigators on Chronic Myeloid Leukemia. The European Leukemia Net has improved leukemia research and management across Europe. Its concept has led to funding by the European Commission as a network of excellence. Other sources (European Science Foundation; European Leukemia Net-Foundation) will take over when the support of the European Commission ends.
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| 4. |
- Mohr, Sebastian, et al.
(författare)
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Hoxa9 and Meis1 Cooperatively Induce Addiction to Syk Signaling by Suppressing miR-146a in Acute Myeloid Leukemia.
- 2017
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Ingår i: Cancer cell. - : Elsevier BV. - 1878-3686 .- 1535-6108. ; 31:4
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Tidskriftsartikel (refereegranskat)abstract
- The transcription factor Meis1 drives myeloid leukemogenesis in the context of Hox gene overexpression butis currently considered undruggable. We therefore investigated whether myeloid progenitor cells transformed by Hoxa9 and Meis1 become addicted to targetable signaling pathways. A comprehensive (phospho)proteomic analysis revealed that Meis1 increased Syk protein expression and activity. Syk upregulation occurs through a Meis1-dependent feedback loop. By dissecting this loop, we show that Syk is a direct target of miR-146a, whose expression is indirectly regulated by Meis1 through the transcription factor PU.1. In the context of Hoxa9 overexpression, Syk signaling induces Meis1, recapitulating several leukemogenic features of Hoxa9/Meis1-driven leukemia. Finally, Syk inhibition disrupts the identified regulatory loop, prolonging survival of mice with Hoxa9/Meis1-driven leukemia.
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| 5. |
- Zhang, Jing, et al.
(författare)
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The Phosphatases STS1 and STS2 Regulate Hematopoietic Stem and Progenitor Cell Fitness.
- 2015
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Ingår i: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 5:4, s. 633-646
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Tidskriftsartikel (refereegranskat)abstract
- FLT3 and c-KIT are crucial regulators of hematopoietic stem and progenitor cells. We investigated the role of STS1 and STS2 on FLT3 and c-KIT phosphorylation, activity, and function in normal and stress-induced hematopoiesis. STS1/STS2-deficient mice show a profound expansion of multipotent progenitor and lymphoid primed multipotent progenitor cells with elevated colony-forming capacity. Although long-term hematopoietic stem cells are not increased in numbers, lack of STS1 and STS2 significantly promotes long-term repopulation activity, demonstrating a pivotal role of STS1/STS2 in regulating hematopoietic stem and progenitor cell fitness. Biochemical analysis identified STS1/STS2 as direct phosphatases of FLT3 and c-KIT. Loss of STS1/STS2 induces hyperphosphorylation of FLT3, enhances AKT signaling, and confers a strong proliferative advantage. Therefore, our study reveals that STS1 and STS2 may serve as novel pharmaceutical targets to improve hematopoietic recovery after bone marrow transplantation.
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