Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.37 (DNA methyltransferase)
 4,983 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have constructed cDNA libraries representing transcripts from purified populations of germ cells and of somatic cells, isolated from fetal mouse gonads at 12.5 days postcoitum (dpc). We have used these libraries to study differential gene expression in fetal germ cells on the basis of differential representation of specific cDNAs in each library. We show that in addition to expression of housekeeping genes at expected levels, four genes responsible for germ cell-specific phenotypes are expressed at significantly different levels in germ cells and surrounding somatic cells. These include tissue-nonspecific alkaline phosphatase (tnAP), transcription factor Oct-3/4, the c-kit proto-oncogene, and DNA methyltransferase (Mt). The significance of these results is discussed in the context of events contributing to early development of germ cells. It is concluded that fetal germ cells appear to retain a pattern of gene expression resembling that in early pluripotent embryonic cells, and that this may be important for the maintenance of genetic totipotency.
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PMID:Differential gene expression in fetal mouse germ cells. 845 33

This study was purposed to investigate the mutational status of DNA methyltransferase (DNMT3a) gene and the clinical features of AML patients with DNMT3a mutations. Using PCR combined with directly sequencing, the somatic mutations of DNMT3a involving residue of amino acid 882 were detected in 77 AML patients. Furthermore, the clinical features of these patients were also studied. The results showed that the DNMT3a mutation were detected in 7 out of 59 patients with de novo AML (11.9%), which included 4 patients with DNMT3a R882C, 2 patients with DNMT3a R882H and 1 patient with DNMT3a Y874C. Morphology examination indicated that 2 patients were M(2), 1 patient was M(4) and 4 patients were M(5). Cytogenetic analysis revealed that karyotype in 5 out of 7 patients with DNMT3a mutation were normal. In total of 27 patients with normal karyotype 5 patients (22.7%) were found harboring DNMT3a mutation, while no DNMT3a mutation was found in 21 patients with abnormal karyotype. The mutation rate in patients with positive CEBPA was obviously higher than that in patients with negative CEBPA (p = 0.002). Immunophenotype analysis showed that 4 patients (4/7, 57.1%) with DNMT3a mutation expressed lymphoid antigens including CD4 or/and CD7. There were no statistical significance in age, gender, blast cells of bone marrow, white blood cell and platelet counts, hemoglobin level, ratio of CR, mutations of FLT3-ITD, NPM1 and c-kit between patients with DNMT3a mutation and patients with wild DNMT3a (p > 0.05). It is concluded that the DNMT3a mutations are more prevalent in AML patients with normal karyotype accompanying with positive NPM1 and/or CEBPA mutation, the role of DNMT3a mutation in AML prognosis needs to be further studied.
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PMID:[Analysis of DNMT3a gene mutations in acute myelogenous leukemia]. 2151 76

Genome sequencing studies of patient samples have implicated the involvement of various components of the epigenetic machinery in myeloid diseases, including the de novo DNA methyltransferase DNMT3A. We have recently shown that Dnmt3a is essential for hematopoietic stem cell differentiation. Here, we investigated the effect of loss of Dnmt3a on hematopoietic transformation by forcing the normally quiescent hematopoietic stem cells to divide in vivo. Mice transplanted with Dnmt3a-null bone marrow in the absence of wildtype support cells succumbed to bone marrow failure (median survival, 328 days) characteristic of myelodysplastic syndromes with symptoms including anemia, neutropenia, bone marrow hypercellularity, and splenomegaly with myeloid infiltration. Two out of 25 mice developed myeloid leukemia with >20%blasts in the blood and bone marrow. Four out of 25 primary mice succumbed to myeloproliferative disorders, some of which progressed to secondary leukemia after long latency. Exome sequencing identified cooperating c-Kit mutations found only in the leukemic samples. Ectopic introduction of c-Kit variants into a Dnmt3a-deficient background produced acute leukemia with a short latency (median survival, 67 days). Our data highlight crucial roles of Dnmt3a in normal and malignant hematopoiesis and suggest that a major role for this enzyme is to facilitate developmental progression of progenitor cells at multiple decision checkpoints.
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PMID:Enforced differentiation of Dnmt3a-null bone marrow leads to failure with c-Kit mutations driving leukemic transformation. 2561 34

The aim of the present study was to elucidate the genetic features of early-onset colorectal cancer (CRC), particularly the genetic mutations that may be regarded as prognostic and/or predictive markers in CRC and other malignancies. In total, 40 patients with non-polyposis CRC aged 35 or younger were selected. The formalin-fixed, paraffin-embedded tumors acquired were subjected to mismatch repair (MMR) protein immunochemical staining and gene analysis with next-generation sequencing (44 exons, 17 genes; Ion Torrent Sequencing Platform). A total of 11 (27.5%) tumors presented with MMR protein deficiency (dMMR) and 26 (65%) tumors harbored one or more genetic mutations, including K-RAS proto-oncogene (35%), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA; 20%), B-Raf proto-oncogene (5%), erb-b2 receptor tyrosine kinase 2 (5%), discoidin domain receptor tyrosine kinase 2 (5%), N-RAS proto-oncogene (2.5%), KIT proto-oncogene (2.5%), TSC complex subunit 1 (2.5%), DNA methyltransferase 3 alpha (2.5%) and ABL proto-oncogene 1 (2.5%). Of the dMMR tumors, 81.8% (9/11) of cases presented with mutations in the tested genes, while only 58.6% (17/29) of the MMR-proficient (pMMR) tumors presented with these (P=0.158). PI3KCA was frequently mutated in dMMR tumors compared to pMMR tumors (P=0.025). In a subgroup with a family history of CRC, the dMMR status (P<0.001) and PIK3CA genetic mutation status (P=0.01) were more frequently observed compared to the other two groups (with a family history of other cancer types or no malignancy). Almost all patients who had relatives with CRC presented with both dMMR and other genetic mutations, while this was not observed in the patients who had relatives with other types of carcinoma. Certain genetic mutations that are rarely reported in CRC were only identified in those patients with a family history of carcinoma. In conclusion, non-polyposis CRC in young adults presents as a distinct entity with a unique set of genetic features. However, investigation of more cases in further studies is required to verify the present results.
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PMID:Early-onset colorectal cancer: A distinct entity with unique genetic features. 3277 6