Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epigenetics refers to the study of clonally inherited changes in gene expression without accompanying genetic changes. Previous research on the epigenetics of myelodysplastic syndromes (MDS) mainly focused on the inactivation of tumor suppressor genes as a result of DNA methylation. However, the basic molecular pathogenesis of epigenetics in MDS remains poorly understood. Recent studies have revealed that DNA methylation and histone modification may be controlled by Polycomb-group (PcG) proteins, which may give new clues toward understanding the epigenetic mechanism of MDS. In this study, we explored for the first time the expression of PcG genes, including EZH2, EED, SUZ12, RING1, and BMI1, in various MDS subsets and acute myeloid leukemia (AML), as well as the relationship between the expression of PcG genes and epigenetic alteration and prognosis-risk scoring. Patients with MDS/AML showed overexpression of EZH2, RING1, and BMI1 genes compared to their expression levels in patients with non-clonal cytopenia diseases. The MDS patients with DNA methylation had higher EZH2 expression than those without DNA methylation. The patients who received decitabine treatment presented significantly reduced expression of EZH2 and RING1 besides decreased p15(INK4B) methylation after decitabine treatment. Moreover, overexpression of EZH2, RING1, and BMI1 was always linked to poor prognostic scoring. In conclusion, overexpression of the EZH2, RING1, and BMI1 genes is common in MDS and indicate poor prognosis. The products of these genes might participate in epigenetic regulation of MDS. These studies may also contribute to our understanding of the effective mechanism of decitabine.
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PMID:Overexpression of the EZH2, RING1 and BMI1 genes is common in myelodysplastic syndromes: relation to adverse epigenetic alteration and poor prognostic scoring. 2112 1

The polycomb repressive complex 2 (PRC2) is a highly conserved histone H3 lysine 27 methyltransferase that regulates the expression of developmental genes. Inactivating mutations of the catalytic component of PRC2, EZH2, are seen in myeloid disorders. We reasoned that the other 2 core PRC2 components, SUZ12 and EED, may also be mutational targets in these diseases, as well as associated factors such as JARID2. SUZ12 mutations were identified in 1 of 2 patients with myelodysplastic syndrome/myeloproliferative neoplasms with 17q acquired uniparental disomy and in 2 of 2 myelofibrosis cases with focal 17q11 deletions. All 3 were missense mutations affecting the highly conserved VEFS domain. Analysis of a further 146 myelodysplastic syndrome/myeloproliferative neoplasm patients revealed an additional VEFS domain mutant, yielding a total mutation frequency of 1.4% (2 of 148). We did not find mutations of JARID2 or EED in association with acquired uniparental disomy for chromosome 6p or 11q, respectively; however, screening unselected cases identified missense mutations in EED (1 of 148; 1%) and JARID2 (3 of 148; 2%). All 3 SUZ12 mutations tested and the EED mutation reduced PRC2 histone methyltransferase activity in vitro, demonstrating that PRC2 function may be compromised in myeloid disorders by mutation of distinct genes.
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PMID:Inactivation of polycomb repressive complex 2 components in myeloproliferative and myelodysplastic/myeloproliferative neoplasms. 2230 77

An unexpected revelation of cancer genome studies has been frequent abnormality in genes for factors that modify chromatin, underscored in this issue of Blood by reports from Score et al and Kroeze et al of inactivating mutations and chromosome loss in SUZ12, EED and JARID2 in myelodysplastic syndrome (MDS) and myeloproliferative disease (MPD).
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PMID:Polycomb segment myeloid malignancies. 2230 84

Therapy-related myelodysplastic syndromes and acute myelogenous leukemia comprise a poor-risk subset of myelodysplastic syndromes and acute myelogenous leukemia. Large-scale mutation profiling efforts in de novo myelodysplastic syndromes have identified mutations that correlate with clinical features, but such mutations have not been investigated in therapy-related myelodysplastic syndromes and acute myelogenous leukemia. Genomic DNA from 38 patient samples were subjected to high throughput polymerase chain reaction and sequenced for TP53, TET2, DNMT3A, ASXL1, IDH1, IDH2, EZH2, EED, SUZ12, RBBP4, SRSF2, U2AF35, and SF3B1. We identified somatic mutations in 16 of 38 (42%) patients. TP53 mutations were the most common lesion, detected in 8 of 38 (21%) patients, followed by TET2 in 4 of 38 (10.5%). Cases with a TP53 mutation or loss of the TP53 locus had a worse overall survival compared to those with wild-type TP53 (8.8 vs. 37.4 months; P=0.0035).
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PMID:Mutational analysis of therapy-related myelodysplastic syndromes and acute myelogenous leukemia. 2334 5

Myelodysplastic syndromes (MDS) are characterized by recurrent somatic alterations often affecting components of RNA splicing machinery. Mutations of splice factors SF3B1, SRSF2, ZRSR2 and U2AF1 occur in >50% of MDS. To assess the impact of spliceosome mutations on splicing and to identify common pathways/genes affected by distinct mutations, we performed RNA-sequencing of MDS bone marrow samples harboring spliceosome mutations (including hotspot alterations of SF3B1, SRSF2 and U2AF1; small deletions of SRSF2 and truncating mutations of ZRSR2), and devoid of other common co-occurring mutations. We uncover the landscape of splicing alterations in each splice factor mutant MDS and demonstrate that small deletions in SRSF2 cause highest number of splicing alterations compared with other spliceosome mutations. Although the mis-spliced events observed in different splice factor mutations were largely non-overlapping, a subset of genes, including EZH2, were aberrantly spliced in multiple mutant groups. We also verified aberrant splicing of key genes USP9X, USP24 (deubiquitinating enzymes), LUC7L2 (splice factor) and EED (PRC2 component) in MDS harboring small deletions of SRSF2. Pathway analysis revealed that mis-spliced genes in different mutant groups were enriched in RNA splicing and transport as well as several signaling cascades, suggesting converging biological consequences downstream of distinct spliceosome mutations. Our study reveals splicing signatures of each splice factor mutation and identifies shared and distinct sets of mis-spliced genes and affected biological processes in different spliceosome mutant MDS.
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PMID:Distinct and convergent consequences of splice factor mutations in myelodysplastic syndromes. 3168 Feb 97