Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.5.7.1 (methylenetetrahydrofolate reductase)
 2,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genome-wide reduction in 5-methylcytosine is an epigenetic hallmark of human tumorigenesis. Experimentally induced hypomethylation in mice promotes genomic instability and is sufficient to initiate tumorigenesis. Here, we report that global hypomethylation is common in primary human glioblastomas [glioblastoma multiforme (GBM)] and can affect up to an estimated 10 million CpG dinucleotides per haploid tumor genome. Demethylation involves satellite 2 (Sat2) pericentromeric DNA at chromosomes 1 and 16, the subtelomeric repeat sequence D4Z4 at chromosomes 4q and 10q, and interspersed Alu elements. Severe hypomethylation of Sat2 sequences is associated with copy number alterations of the adjacent euchromatin, suggesting that hypomethylation may be one factor predisposing to specific genetic alterations commonly occurring in GBMs. An additional apparent consequence of global hypomethylation is reactivation of the cancer-testis antigen MAGEA1 via promoter demethylation, but only in GBMs and GBM cell lines exhibiting a 5-methylcytosine content below a threshold of approximately 50%. Primary GBMs with significant hypomethylation tended to be heterozygous or homozygous for the low-functioning Val allele of the rate-limiting methyl group metabolism gene methylenetetrahydrofolate reductase (MTHFR), or had a deletion encompassing this gene at 1p36. Tumors with severe genomic hypomethylation also had an elevated proliferation index and deletion of the MTHFR gene. These data suggest a model whereby either excessive cell proliferation in the context of inadequate methyl donor production from MTHFR deficiency promotes genomic hypomethylation and further genomic instability, or that MTHFR deficiency-associated demethylation leads to increased proliferative activity in GBM.
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PMID:Genome-wide hypomethylation in human glioblastomas associated with specific copy number alteration, methylenetetrahydrofolate reductase allele status, and increased proliferation. 1695 Nov 58

Genetic polymorphisms of methionine metabolism, in particular methionine synthase (MTR) c.2756A>G (D919G) and methylenetetrahydrofolate reductase (MTHFR) c.677C>T (A222V), have been associated with various human cancers. We investigated MTR c.2756A>G, MTHFR c.677C>T, and a third polymorphism, transcobalamin 2 c.776C>G (P259R), for a potential association with the formation of glioblastoma multiforme. The MTR c.2756G allele was significantly underrepresented among 328 glioblastoma multiforme patients of Caucasian origin when compared with 400 population controls [patients AA/AG/GG: 0.72/0.26/0.02 and controls AA/AG/GG: 0.57/0.38/0.05, degrees of freedom = 2; chi(2) = 17.86 (Pearson); P < 0.001]. No association between glioblastoma multiforme and the two other polymorphisms was observed.
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PMID:The methionine synthase polymorphism c.2756A>G alters susceptibility to glioblastoma multiforme. 1711 65

Glioblastoma multiforme (GBM) is the most frequent primary brain tumor in adults. Prognosis is poor. Using a series of 214 GBM patients, we observed an effect of the variant 5,10-methylenetetrahydrofolate reductase (MTHFR) c.677C>T on overall survival. This effect was strongest in patients younger than 60 years at diagnosis (overall survival, median +/- SE: genotype CC, 13 +/- 1 months; CT, 11 +/- 2 months; TT, 7 +/- 3 months; multivariate Cox regression analysis, Wald = 8.58, p = 0.007). In addition, the MTHFR genotype significantly influenced the overall survival of patients with a postoperative Karnofsky score >70 (CC, 12 +/- 2 months; CT, 11 +/- 1 months; TT, 10 +/- 4 months; Wald = 5.89, p = 0.015). These data suggest the MTHFR c.677C>T variant is a risk factor for survival in GBM patients.
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PMID:The methylenetetrahydrofolate reductase (MTHFR) variant c.677C>T (A222V) influences overall survival of patients with glioblastoma multiforme. 1849 26