| 1. |
- Mead, Adam J., et al.
(författare)
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FLT3-ITDs Instruct a Myeloid Differentiation and Transformation Bias in Lymphomyeloid Multipotent Progenitors
- 2013
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 3:6, s. 1766-1776
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Tidskriftsartikel (refereegranskat)abstract
- Whether signals mediated via growth factor receptors (GFRs) might influence lineage fate in multipotent progenitors (MPPs) is unclear. We explored this issue in a mouse knockin model of gain-of-function Flt3-ITD mutation because FLT3-ITDs are paradoxically restricted to acute myeloid leukemia even though Flt3 primarily promotes lymphoid development during normal hematopoiesis. When expressed in MPPs, Flt3-ITD collaborated with Runx1 mutation to induce high-penetrance aggressive leukemias that were exclusively of the myeloid phenotype. Flt3-ITDs preferentially expanded MPPs with reduced lymphoid and increased myeloid transcriptional priming while compromising early B and T lymphopoiesis. Flt3-ITD-induced myeloid lineage bias involved upregulation of the transcription factor Pu.1, which is a direct target gene of Stat3, an aberrantly activated target of Flt3-ITDs, further establishing how lineage bias can be inflicted on MPPs through aberrant GFR signaling. Collectively, these findings provide new insights into how oncogenic mutations might subvert the normal process of lineage commitment and dictate the phenotype of resulting malignancies.
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| 2. |
- Svensson, Tobias, et al.
(författare)
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A pilot phase I dose finding safety study of the thrombopoietin-receptor agonist, eltrombopag, in patients with myelodysplastic syndrome treated with azacitidine
- 2014
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 93:5, s. 439-445
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Thrombocytopenia is an independent adverse prognostic factor in patients with Myelodysplastic syndromes (MDS). Azacitidine, first-line treatment for the majority of patients with higher-risk MDS, is associated with aggravated thrombocytopenia during the first cycles. Eltrombopag is a novel thrombopoietin receptor agonist, which also has been shown to inhibit proliferation of leukaemia cell lines in vitro. This phase I clinical trial was designed to explore the safety and tolerability of combining eltrombopag with azacitidine in patients with MDS. In addition, we assessed the potential effects of eltrombopag on hematopoietic stem and progenitor cells (HSPCs) from included patients.Patients and methods: Previously untreated patients with MDS eligible for treatment with azacitidine and with a platelet count <75x10(9)/L were included. Patients received eltrombopag in dose escalation cohorts during three cycles of azacitidine.Results: Twelve patients, with a median age of 74yr, were included. Severe adverse events included infectious complications, deep vein thrombosis and transient ischaemic attack. The maximal tolerated eltrombopag dose was 200mg qd. Complete remission or bone marrow remission was achieved in 4 of 12 patients. Platelet counts improved or remained stable in 9 of 12 patients despite azacitidine treatment. No increase in blast count, disease progression, or bone marrow fibrosis related to study medication was reported. Eltrombopag did not induce cycling of HSPCs.Conclusion: The combination of eltrombopag with azacitidine in high-risk MDS patients is feasible and well tolerated. Improvements in platelet counts and the potential antileukaemic effect of eltrombopag should be explored in a randomised study.
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| 3. |
- Woll, Petter S, et al.
(författare)
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Myelodysplastic Syndromes Are Propagated by Rare and Distinct Human Cancer Stem Cells In Vivo.
- 2014
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Ingår i: Cancer Cell. - : Elsevier BV. - 1878-3686 .- 1535-6108. ; 25:6, s. 794-808
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Tidskriftsartikel (refereegranskat)abstract
- Evidence for distinct human cancer stem cells (CSCs) remains contentious and the degree to which different cancer cells contribute to propagating malignancies in patients remains unexplored. In low- to intermediate-risk myelodysplastic syndromes (MDS), we establish the existence of rare multipotent MDS stem cells (MDS-SCs), and their hierarchical relationship to lineage-restricted MDS progenitors. All identified somatically acquired genetic lesions were backtracked to distinct MDS-SCs, establishing their distinct MDS-propagating function in vivo. In isolated del(5q)-MDS, acquisition of del(5q) preceded diverse recurrent driver mutations. Sequential analysis in del(5q)-MDS revealed genetic evolution in MDS-SCs and MDS-progenitors prior to leukemic transformation. These findings provide definitive evidence for rare human MDS-SCs in vivo, with extensive implications for the targeting of the cells required and sufficient for MDS-propagation.
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