Analysis of DNA methyltransferase 3A gene mutations in patients with Philadelphia-negative myeloproliferative neoplasms

2017 ◽  
Vol 6 (1) ◽  
pp. 81
Author(s):  
Najmaldin Saki ◽  
Neda Ketabchi ◽  
Mostafa Paridar ◽  
Javad Mohammadi-Asl ◽  
Alireza Abooali ◽  
...  
Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2506-2506
Author(s):  
Aline Renneville ◽  
Nicolas Boissel ◽  
Olivier Nibourel ◽  
Céline Berthon ◽  
Nathalie Helevaut ◽  
...  

Abstract Abstract 2506 Introduction: The development of massively parallel sequencing technologies has led to the identification of somatic DNA methyltransferase 3A (DNMT3A) gene mutations in acute myeloid leukemia (AML), with the highest frequency being found in cytogenetically normal (CN) AML. DNMT3A mutations have been suggested to predict poor clinical outcome in AML, but only few data are available on their prognostic significance within CN-AML. The aim of this study was to determine the frequency, the main associated features, and the prognostic significance of DNMT3A mutations in CN-AML. Patients and methods: This retrospective study was performed in 123 young adult patients (16–60 years) with previously untreated primary CN-AML and enrolled on two concomitant protocols of the Acute French Leukemia Association (ALFA), the ALFA-9801 and ALFA-9802 trials. DNMT3A mutations were screened on genomic DNA by PCR and direct Sanger sequencing. We focused our screening on the 3 conserved domains of DNMT3A (the proline-tryptophane-tryptophane-proline (PWWP) domain, the ADD-type zinc finger domain, and the C5-methyltransferase domain), corresponding to exons 8–9 and 11–23. The patients were also assessed for the presence of FLT3 internal tandem duplication (FLT3-ITD), FLT3 tyrosine kinase domain (FLT3-TKD), NPM1, CEBPA, WT1, IDH1, and IDH2 mutations. Results: Thirty-eight DNMT3A mutations were identified in 36 of the 123 (29%) patients. These alterations consisted of 36 nucleotide substitutions and 2 frameshift deletions. Thirty out of 36 (83%) nucleotide substitutions affected the amino acid residue R882 (R882H, n = 21; R882C, n = 7; R882P, n = 2), 5 represented other missense alterations, and 1 was a nonsense mutation. Two patients exhibited 2 heterozygous missense mutations in different exons, and one patient had a homozygous missense mutation. DNMT3A mutated and wild-type cases did not differ in terms of age, gender, and white blood cell (WBC) count at presentation. DNMT3A mutations were strongly associated with the French-American-British (FAB) subtypes M4/M5 (P =.0002) and the presence of NPM1 mutations (P =.0006), and tended to often co-occur with IDH1R132 mutations (P = .09). In the entire cohort, complete remission rate was found lower in DNMT3A mutated patients than in DNMT3A wild-type patients, but without reaching statistical significance (80% vs 90%, P =.24). DNMT3A mutated patients had a shorter event-free survival (5-year EFS: 13% vs 32%, P =.02) and overall survival (5-year OS: 23% vs 45%, P =.02) compared to DNMT3A wild-type patients. We next performed subgroup analysis according to the NPM1/FLT3-ITD genotypes. In patients with the non-favorable genotypes, that is NPM1 mutated/FLT3-ITD positive, NPM1 wild-type/FLT3-ITD positive, NPM1 wild-type/FLT3-ITD negative (n = 86), 18 (21%) had a concomitant DNMT3A mutation. In this high-risk subgroup of CN-AML, DNMT3A mutations conferred a worse clinical outcome (5-year EFS: 0% vs 23%, P =.02; 5-year OS: 14% vs 37%, P =.06). In patients with the favorable genotype NPM1 mutated/FLT3-ITD negative (n = 37), 18 (49%) were found to display a concomitant DNMT3A mutation. Within this favorable subgroup, patients carrying a DNMT3A mutation had a significantly inferior EFS and OS compared to DNMT3A wild-type patients (5-year EFS: 25% vs 65%, P =.01; 5-year OS: 29% vs 76%, P =.02). Furthermore, in multivariate analysis including age, WBC count, NPM1/FLT3-ITD genotypes, and DNMT3A mutational status, the presence of a DNMT3A mutation remained an independent adverse prognostic factor for EFS (hazard ratio = 2.29; 95% CI, 1.42 to 3.70; P =.0007) and OS (hazard ratio = 2.34; 95% CI, 1.37 to 4.00; P =.002). Conclusion: DNMT3A mutations are one of the most common gene mutations in CN-AML and independently predict poor clinical outcome. Testing for DNMT3A mutations could help further improve risk stratification in CN-AML. Disclosures: No relevant conflicts of interest to declare.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3078
Author(s):  
Yuh Cai Chia ◽  
Md Asiful Islam ◽  
Phil Hider ◽  
Peng Yeong Woon ◽  
Muhammad Farid Johan ◽  
...  

Multiple recurrent somatic mutations have recently been identified in association with myeloproliferative neoplasms (MPN). This meta-analysis aims to assess the pooled prevalence of TET2 gene mutations among patients with MPN. Six databases (PubMed, Scopus, ScienceDirect, Google Scholar, Web of Science and Embase) were searched for relevant studies from inception till September 2020, without language restrictions. The eligibility criteria included BCR-ABL-negative MPN adults with TET2 gene mutations. A random-effects model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Subgroup analyses explored results among different continents and countries, WHO diagnostic criteria, screening methods and types of MF. Quality assessment was undertaken using the Joanna Briggs Institute critical appraisal tool. The study was registered with PROSPERO (CRD42020212223). Thirty-five studies were included (n = 5121, 47.1% female). Overall, the pooled prevalence of TET2 gene mutations in MPN patients was 15.5% (95% CI: 12.1–19.0%, I2 = 94%). Regional differences explained a substantial amount of heterogeneity. The prevalence of TET2 gene mutations among the three subtypes PV, ET and MF were 16.8%, 9.8% and 15.7%, respectively. The quality of the included studies was determined to be moderate–high among 83% of the included studies. Among patients with BCR-ABL-negative MPN, the overall prevalence of TET2 gene mutations was 15.5%.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Isabella Loughland ◽  
Alexander Little ◽  
Frank Seebacher

Abstract Background Thermal plasticity is pivotal for evolution in changing climates and in mediating resilience to its potentially negative effects. The efficacy to respond to environmental change depends on underlying mechanisms. DNA methylation induced by DNA methyltransferase 3 enzymes in the germline or during early embryonic development may be correlated with responses to environmental change. This developmental plasticity can interact with reversible acclimation within adult organisms, which would increase the speed of response and could alleviate potential mismatches between parental or early embryonic environments and those experienced at later life stages. Our aim was to determine whether there is a causative relationship between DNMT3 enzyme and developmental thermal plasticity and whether either or both interact with short-term acclimation to alter fitness and thermal responses in zebrafish (Danio rerio). Results We developed a novel DNMT3a knock-out model to show that sequential knock-out of DNA methyltransferase 3a isoforms (DNMT3aa−/− and DNMT3aa−/−ab−/−) additively decreased survival and increased deformities when cold developmental temperatures in zebrafish offspring mismatched warm temperatures experienced by parents. Interestingly, short-term cold acclimation of parents before breeding rescued DNMT3a knock-out offspring by restoring survival at cold temperatures. DNMT3a knock-out genotype interacted with developmental temperatures to modify thermal performance curves in offspring, where at least one DNMT3a isoform was necessary to buffer locomotion from increasing temperatures. The thermal sensitivity of citrate synthase activity, an indicator of mitochondrial density, was less severely affected by DNMT3a knock-out, but there was nonetheless a significant interaction between genotype and developmental temperatures. Conclusions Our results show that DNMT3a regulates developmental thermal plasticity and that the phenotypic effects of different DNMT3a isoforms are additive. However, DNMT3a interacts with other mechanisms, such as histone (de)acetylation, induced during short-term acclimation to buffer phenotypes from environmental change. Interactions between these mechanisms make phenotypic compensation for climate change more efficient and make it less likely that thermal plasticity incurs a cost resulting from environmental mismatches.


2020 ◽  
Vol 102 (1) ◽  
pp. 45-50
Author(s):  
Hebah Ali ◽  
Ignazio Puccio ◽  
Ayse U. Akarca ◽  
Roshanak Bob ◽  
Sabine Pomplun ◽  
...  

Oncogene ◽  
2014 ◽  
Vol 34 (14) ◽  
pp. 1822-1830 ◽  
Author(s):  
B Weis ◽  
J Schmidt ◽  
H Maamar ◽  
A Raj ◽  
H Lin ◽  
...  

2021 ◽  
Vol 22 (18) ◽  
pp. 9867
Author(s):  
Yi-Chun Huang ◽  
Chao-Yung Wang

Clinical evidence suggests that conventional cardiovascular disease (CVD) risk factors cannot explain all CVD incidences. Recent studies have shown that telomere attrition, clonal hematopoiesis of indeterminate potential (CHIP), and atherosclerosis (telomere–CHIP–atherosclerosis, TCA) evolve to play a crucial role in CVD. Telomere dynamics and telomerase have an important relationship with age-related CVD. Telomere attrition is associated with CHIP. CHIP is commonly observed in elderly patients. It is characterized by an increase in blood cell clones with somatic mutations, resulting in an increased risk of hematological cancer and atherosclerotic CVD. The most common gene mutations are DNA methyltransferase 3 alpha (DNMT3A), Tet methylcytosine dioxygenase 2 (TET2), and additional sex combs-like 1 (ASXL1). Telomeres, CHIP, and atherosclerosis increase chronic inflammation and proinflammatory cytokine expression. Currently, their epidemiology and detailed mechanisms related to the TCA axis remain incompletely understood. In this article, we reviewed recent research results regarding the development of telomeres and CHIP and their relationship with atherosclerotic CVD.


2014 ◽  
Vol 60 (2) ◽  
pp. 44-48
Author(s):  
Annamária Szántó ◽  
Zsuzsanna Pap ◽  
Z Pávai ◽  
I Benedek ◽  
Judit Beáta Köpeczi ◽  
...  

Abstract Background: The elucidation of the genetic background of the myeloproliferative neoplasms completely changed the management of these disorders: the presence of the Philadelphia chromosome and/or the BCR-ABL oncogene is pathognomonic for chronic myeloid leukemia and identification of JAK2 gene mutations are useful in polycytemia vera (PV), essential thrombocytemia (ET) and myelofibrosis (PMF). The aim of this study was to investigate the role of molecular biology tests in the management of myeloproliferative neoplasms. Materials and methods: We tested the blood samples of 117 patients between April 2008 and February 2013 at the Molecular Biology of UMF Târgu Mureș using RQ-PCR (for M-BCR-ABL oncogene) and/or allele-specific PCR (for JAK2V617F mutation). Results: Thirty-two patients presented the M-BCR-ABL oncogene, 16 of them were regularly tested as a follow-up of the administered therapy: the majority of chronic phase patients presented decreasing or stable values, while in case of accelerated phase and blast phase the M-BCR-ABL values increased or remained at the same level. Twenty patients were identified with the JAK2V617F mutation: 8 patients with PV, 4 with ET, 3 with PMF, 4 with unclassifiable chronic myeloproliferative disease and 1 patient with chronic myelomonocytic leukemia. There was no case of concomitant occurance of both molecular markers. Conclusions: Molecular biology testing plays an important role in the management of myeloproliferative neoplasms: identification of the molecular markers confirms the final diagnosis, excluding secondary causes of abnormal blood count parameters. Regular monitoring of MBCR- ABL expression level is useful in the follow-up of therapeutic efficiency.


2021 ◽  
Author(s):  
Masaki Shirai ◽  
Takuya Nara ◽  
Haruko Takahashi ◽  
Kazuya Takayama ◽  
Yuan Chen ◽  
...  

CpG methylation in genomic DNA is well known as a repressive epigenetic marker in eukaryotic transcription, and DNA methylation of the promoter regions is correlated with silencing of gene expression. In contrast to the promoter regions, the function of DNA methylation during transcription termination remains to be elucidated. A recent study has revealed that mouse DNA methyltransferase 3a (Dnmt3a) mainly functions in de novo methylation in the promoter and gene body regions (including transcription termination sites (TTSs)) during development. To investigate the relationship between DNA methylation overlapping the TTSs and transcription termination, we employed two strategies: informatic analysis using already deposited datasets of Dnmt3a-/- mouse cells and the zebrafish model system. Bioinformatic analysis using methylome and transcriptome data showed that hypomethylated differentially methylated regions overlapping the TTSs were associated with increased read counts and chimeric transcripts downstream of TTSs in Dnmt3a-/- Agouti-related protein neurons, but not in Dnmt3a-/- ES cells and MEFs. We experimentally detected increased read-through and chimeric transcripts downstream of hypomethylated TTSs in zebrafish maternal-zygotic dnmt3aa-/- mutants. This study is the first to identify transcription termination defects in DNA hypomethylated TTSs in Dnmt3a-/- vertebrates.


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