Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The myelodysplastic syndromes (MDSs) are a heterogeneous group of clonal haematological diseases characterized by ineffective haematopoiesis and predisposition to acute myeloid leukaemia (AML). The pathophysiology of MDSs remains unclear. A definition of the molecular biology of MDSs may lead to a better classification, new prognosis indicators and new treatments. We studied a series of 40 MDS/AML samples by high-density array-comparative genome hybridization (aCGH). The genome of MDSs displayed a few alterations that can point to candidate genes, which potentially regulate histone modifications and WNT pathways (e.g. ASXL1, ASXL2, UTX, CXXC4, CXXC5, TET2, TET3). To validate some of these candidates we studied the sequence of ASXL1. We found mutations in the ASXL1 gene in four out of 35 MDS patients (11%). To extend these results we searched for mutations of ASXL1 in a series of chronic myelomonocytic leukaemias, a disease classified as MDS/Myeloproliferative disorder, and found mutations in 17 out of 39 patients (43%). These results show that ASXL1 might play the role of a tumour suppressor in myeloid malignancies.
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PMID:Mutations of polycomb-associated gene ASXL1 in myelodysplastic syndromes and chronic myelomonocytic leukaemia. 1938 38

Chronic myelomonocytic leukaemia (CMML) is a clonal haematopoietic stem cell disorder with myelodysplastic and myeloproliferative overlap features, and an inherent tendency to transform to acute myeloid leukaemia. Approximately 30% of patients present with clonal cytogenetic abnormalities, while almost 90% have molecular aberrations involving epigenetic regulation, the spliceosome component machinery, tumour suppressor genes and transcription factors/regulators. Numerous prognostic models exist for CMML, with more recent models incorporating prognostic mutations, such as those involving ASXL1. Other variables that seem to consistently affect outcomes include the degree of leucocytosis/monocytosis, anaemia and thrombocytopenia. Allogeneic stem cell transplant remains the only curative option for CMML, while hypomethylating agents can be used for transplant-ineligible patients or those without suitable stem cell sources. Targeting biological pathways activated in CMML offers potential hope for more effective and less toxic therapies.
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PMID:Chronic myelomonocytic leukaemia: a concise clinical and pathophysiological review. 2446 17

Additional sex combs-like (ASXL) proteins are mammalian homologues of additional sex combs (Asx), a regulator of trithorax and polycomb function in Drosophila. While there has been great interest in ASXL1 due to its frequent mutation in leukemia, little is known about its paralog ASXL2, which is frequently mutated in acute myeloid leukemia patients bearing the RUNX1-RUNX1T1 (AML1-ETO) fusion. Here we report that ASXL2 is required for normal haematopoiesis with distinct, non-overlapping effects from ASXL1 and acts as a haploinsufficient tumour suppressor. While Asxl2 was required for normal haematopoietic stem cell self-renewal, Asxl2 loss promoted AML1-ETO leukemogenesis. Moreover, ASXL2 target genes strongly overlapped with those of RUNX1 and AML1-ETO and ASXL2 loss was associated with increased chromatin accessibility at putative enhancers of key leukemogenic loci. These data reveal that Asxl2 is a critical regulator of haematopoiesis and mediates transcriptional effects that promote leukemogenesis driven by AML1-ETO.
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PMID:ASXL2 is essential for haematopoiesis and acts as a haploinsufficient tumour suppressor in leukemia. 2851 57