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)

Endometrial polyps and endometrial neoplasms are a recognized complication of chronic tamoxifen treatment. This study describes an endometrial carcinoma that developed in a woman receiving low-dose tamoxifen treatment for breast cancer. Little is known about steroid receptor status, somatic alterations in oncogenes and tumor suppressor genes, and inherited susceptibility in endometrial carcinomas associated with tamoxifen use. In the present case, the endometrial carcinoma was negative for estrogen receptors and weakly positive for progesterone receptors. In addition, analysis of K-ras, c-erbB2/neu, cyclin D1, and p53 status revealed a codon 12 point mutation in the K-ras oncogene. The patient was determined not to be a carrier of germ-line mutations in cytochrome P-450 1A1 (CYP1A1), an estrogen-metabolizing gene previously associated with enhanced endometrial cancer risk, but she was a carrier of a methylenetetrahydrofolate reductase gene variant related with putative alterations in DNA methylation.
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PMID:Endometrial carcinoma in tamoxifen-treated breast cancer patient: clinicopathological, immunohistochemical, and genetic analysis. 1054 49

Diagnosis of inherited diseases or cancer predispositions frequently involves determination of specific mutations or polymorphisms. The number of characterized monogenetic and polygenetic diseases is significantly rising every year. As a result, an increasing number of patient samples with a rising complexity of genetic diseases require molecular diagnostics. In order to apply genetic analyses to large groups of patients or population screening, automation of a sensitive and precise method is highly desirable. Capillary electrophoresis (CE) facilitates the development of methods which can rapidly process large number of patient samples in an automated fashion. In contrast, conventional techniques including Southern blotting, sequencing or standard gel electrophoresis are time consuming, cost ineffective and require substantial amounts of each specimen. Robustness, ease of operation, good reproducibility and low cost are the main advantages of CE. Currently, most protocols adapted to automated CE represent (i) analyses of DNA fragment length or DNA restriction patterns (RFLP), (ii) analyses of single-strand conformation polymorphism (SSCP) and (iii) microsatellite analyses. Recently, automated detection of variations in the FRAXA (CGG)n region (fragile X syndrome), LDL receptor gene, p53 gene, MTHFR (methylenetetrahydrofolate reductase) gene, HFE gene and others has been established on CE systems. These applications clearly demonstrate the suitability of CE for high throughput screening in medical applications.
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PMID:Use of capillary electrophoresis for high throughput screening in biomedical applications. A minireview. 1112 15

Treatment-related leukemias are one of the most devastating late complications of cancer therapy. Patients with rare cancer predisposition syndromes including neurofibromatosis type 1 and inherited p53 mutations are at an increased risk for this complication. Other patients may have increased susceptibility because they possess common genetic polymorphisms in drug-metabolizing enzymes that result in impaired detoxification of chemotherapy or inefficient repair of drug-induced genetic damage. We review studies that have identified a potential role for polymorphisms in the genes encoding the glutathione-S-transferases (GSTs), NAD(P) H: quinone oxidoreductase, myeloperoxidase, N-acetyltransferase (NATs), cytochrome P450 (CYP) 1A1 and 3A4, methylenetetrahydrofolate reductase (MTHFR), cystathionine-beta-synthase (CBS), and others in the etiology of primary or secondary acute leukemias, and therapy-related complications. The identification of high risk polymorphisms and use of pharmacogenetically-guided therapies holds promise to improve the outcome of cancer therapy and reduce the risk of treatment-related leukemias.
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PMID:Genetic predisposition and treatment-related leukemia. 1134 Jun 9

In an exploratory study, 11 common polymorphisms were examined for contributing to longevity including: apolipoprotein E (apoE), methylenetetrahydrofolate reductase (MTHFR), cathepsin D (CAD), superoxide dismutase 2 (SOD2), angiotensinogen (AGT) and insulin-like growth factor 2 (IGF2), Leiden factor 7, p53 oncogene, dopamine D4 receptor (DRD4) and the serotonin transporter (SERT). Genotype and allele frequencies of these genes were compared in 224 older (75 years) Jewish Jerusalem residents of Ashkenazi ethnicity to a group of 441 younger subjects (22 years). Nominally significant results provide suggestive evidence in the Ashkenazi group that apoE, MHTFR, SOD2, IGF2 ApaI, and factor VII are risk factors for a single outcome, survival to 75. Overall, the more genetically homogenous Ashkenazi ethnic group showed evidence for association in five genes examined suggesting that future studies in this population would gainfully focus on this ethnic group.
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PMID:Candidate genes associated with ageing and life expectancy in the Jerusalem longitudinal study. 1562 Dec 15

The role of various enzymes in folate dependent one-carbon metabolism, which are involved in mobilizing the folate pool for DNA synthesis and the DNA methylation reaction, was investigated. Male Swiss mice (6 weeks old) were subjected to 2, 5 and 7 Gy total body gamma-irradiation. The animals were killed at intervals of 24, 48, 72, 96, 120 and 192 h and the livers were removed. Using a 12000 x g supernatant of 10% tissue homogenate, the activities of dihydrofolate reductase, thymidylate synthase and methylenetetrahydrofolate reductase were determined. The profiles of these folate enzymes were correlated to DNA damage by monitoring p53 protein profile and by comet tail moment analysis. A significant increase in activity of dihydrofolate reductase and thymidylate synthase was observed up to 96 h post-irradiation and the activity subsided thereafter, reaching control value after 192 h. A sharp decline in methylenetetrahydrofolate reductase activity was observed until 192 h after irradiation. Total folates declined by 54% after 96 h following irradiation, and p53 protein concentration in nuclei increased after irradiation, proportionate to radiation dose, and subsided slowly. Thus results indicate a significant drop in total folate levels and rise in p53 protein concentration in the liver after total body gamma-irradiation. It may appear that, under radiation stress conditions, levels of enzymes involved in one-carbon metabolism for DNA repair, are modulated up to a certain time interval, in a dose specific manner. It may also appear that the requirements of folate for nucleotide base synthesis seem to be met at the expense of other one-carbon transfer reactions.
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PMID:Modulation of enzymes involved in folate dependent one-carbon metabolism by gamma-radiation stress in mice. 1563 62

Multimodal treatment protocols are increasingly employed to improve the survival of patients with locally advanced adenocarcinomas of the upper gastrointestinal tract, however, only 30-40% per year of the patients respond to 5-FU and cisplatin-based neoadjuvant chemotherapy. The goal of our studies is the identification of reliable genetic markers, on the genomic DNA-level, mRNA, or protein level that could predict response of upper gastrointestinal carcinomas prior to neoadjuvant chemotherapy. In esophageal carcinomas, a higher gene expression of methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in folate metabolism, was more frequently found in responding patients. In addition high gene expression of caldesmon and of the two drug carrier proteins, MRP1 and MDR1 was associated with response to therapy. By performing a genome-wide profiling on the protein level in a small group of patients, new potential markers were identified, which have to be validated in ongoing studies. In gastric carcinomas, mutations of the p53 gene revealed no association with response or survival, but tumors with a high rate of loss of heterozygosity (LOH), determined by microsatellite analysis, showed a better response to a cisplatin-based chemotherapy. Analysis of expression of 5-FU-(e.g., TS, DPD, and TP) and cisplatin-(e.g., ERCC1, ERCC4, GADD45A, and KU80) related genes, demonstrated an association of DPD expression with response and survival. The combined consideration of TP and GADD45 gene expression, showed the most obvious association with therapy response in this tumor. Our studies point to promising markers with potential use for chemotherapy response prediction of adenocarcinomas of the upper gastrointestinal tract, but prospective studies for validation are necessary.
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PMID:Prediction of response to neoadjuvant chemotherapy in carcinomas of the upper gastrointestinal tract. 1716 61

Increasingly, multimodal treatment protocols are being employed to improve the survival of patients with locally advanced adenocarcinomas of the upper gastrointestinal tract; however, only 30%-40% of the patients respond to 5-fluoro-uracil (5-FU) and cisplatin-based neoadjuvant chemotherapy. The goal of our studies is the identification of reliable genetic markers--on the genomic DNA, messenger RNA (mRNA), or protein level-that could predict response of upper gastrointestinal carcinomas prior to neoadjuvant chemotherapy. In esophageal carcinomas, a higher gene expression of methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in folate metabolism, was more frequently found in responding patients. In addition high gene expression of caldesmon and of the two drug carrier proteins MRP1 and MDR1 was associated with response to therapy. By performing a genome-wide profiling on the protein level in a small group of patients, new potential markers were identified that will have to be validated in ongoing studies. In gastric carcinomas, mutations of the p53 gene revealed no association with response or survival, but tumors with a high rate of loss of heterozygosity, as determined by microsatellite analysis, showed a better response to a cisplatin-based chemotherapy. Analysis of the expression of 5-fluorouracil (5-FU) (TS, DPD, TP)- and cisplatin (ERCC1, ERCC4, GADD45A, KU80)-related genes demonstrated an association of DPD expression with response and survival. The combined consideration of TP and GADD45 gene expression showed the most obvious association with therapy response in this tumor. Our studies point to promising markers with potential use for chemotherapy response prediction of adenocarcinomas of the upper gastrointestinal tract, but prospective studies for validation are necessary.
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PMID:Prediction of response to neoadjuvant chemotherapy in carcinomas of the upper gastrointestinal tract. 1760 14

Sufficient folate intake confers positive health benefits, while deficiency is linked with many health problems. Although the US policy of dietary folic acid fortification has reduced the incidence of these deficiency-related health problems, recent evidence has demonstrated an association between folic acid supplementation and increased colorectal cancer incidence. Few studies have explored the possibility that folate affects other slowly developing cancers. This study sought to determine whether folic acid supplementation is sufficient to alter the growth and development of existing oral cancers. A series of in vitro growth, viability, and adhesion assays were performed using the well-characterized human oral squamous cell carcinoma cell lines, CAL27 and SCC25, to determine the effects of folic acid supplementation. Folic acid administration significantly stimulated CAL27 and SCC25 proliferation in a dose-dependent manner, but it was not sufficient to increase proliferation at any concentration tested in the normal control cell line, HGF-1. Neither oral cancer cell line harbored the common C677T DNA polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene, which might reduce folate bioavailability. Overexpression of p53 mRNA was observed in both cancerous cell lines, but it was differentially altered by folic acid administration in only SCC25 cells. These findings suggest folic acid administration may significantly alter growth of oral cancers in vitro via p53-dependent and p53-independent pathways. As oral cancer rates continue to rise in specific geographic areas, and among specific subsets of the US population, understanding environmental mediators, such as folic acid supplementation, becomes increasingly important for nutrition and public health scientists.
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PMID:Folate supplementation induces differential dose-dependent modulation of proliferative phenotypes among cancerous and noncancerous oral cell lines in vitro. 2243 62

Identifying susceptible genes associated with the pathogenesis of atherosclerosis (ATH) may contribute toward better management of this condition. This preliminary study was aimed at assessing the expression levels of 11 candidate genes, namely tumor protein (TP53), transforming growth factor, beta receptor II (TGFBR2), cysthathionenine-beta-synthase (CBS), insulin receptor substrate 1 (IRS1), lipoprotein lipase (LPL), methylenetetrahydrofolate reductase (MTHFR), thrombomodulin (THBD), lecithin-cholesterol acyltransferase (LCAT), matrix metallopeptidase 9 (MMP9), low density lipoprotein receptor (LDLR), and arachidonate 5-lipoxygenase-activating protein (ALOX5AP) genes associated with ATH. Twelve human coronary artery tissues (HCATs) were obtained from deceased subjects who underwent post-mortem procedures. Six atherosclerotic coronary artery tissue (ACAT) samples representing the cases and non-atherosclerotic coronary artery tissue (NCAT) samples as controls were gathered based on predetermined inclusion and exclusion criteria. Gene expression levels were assessed using the GenomeLab Genetic Analysis System (GeXP). The results showed that LDLR, TP53, and MMP9 expression levels were significantly increased in ACAT compared to NCAT samples (p < 0.05). Thus, LDLR, TP53, and MMP9 genes may play important roles in the development of ATH in a Malaysian study population.
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PMID:Preliminary assessment of differential expression of candidate genes associated with atherosclerosis. 2402 48

Folates are B-vitamins that play an important role in brain function. Dietary and genetic deficiencies in folate metabolism result in elevated levels of homocysteine which have been linked to increased risk of developing a stroke. Reducing levels of homocysteine before or after a stroke through B-vitamin supplementation has been a focus of many clinical studies, however, the results remain inconsistent. Animal model systems provide a powerful mechanism to study and understand functional impact and mechanisms through which supplementation affects stroke recovery. The aim of this study was to understand the role of B-vitamins in stroke pathology using in vivo and in vitro mouse models. The first objective assessed the impact of folate deficiency prior to ischemic damage followed by B-vitamins and choline supplementation. Ischemic damage targeted the sensorimotor cortex. C57Bl/6 wild-type mice were maintained on a folic acid deficient diet for 4weeks prior to ischemic damage to increased levels of plasma homocysteine, a risk factor for stroke. Post-operatively mice were placed on a B-vitamin and choline supplemented diet for a period of four weeks, after which motor function was assessed in mice using the rotarod, ladder beam and forepaw asymmetry tasks. The second objective was to determine how a genetic deficiency in methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in folate metabolism, increases vulnerability to stroke. Primary cortical neurons were isolated from Mthfr+/+, Mthfr+/- and Mthfr-/- embryos and were exposed to in vitro models of stroke which include hypoxia or oxygen glucose deprivation. Cell viability was measured 24-h after exposure stroke like conditions in vitro. In supplemented diet mice, we report improved motor function after ischemic damage compared to mice fed a control diet after ischemic damage. Within the perilesional cortex, we show enhanced proliferation, neuroplasticity and anti-oxidant activity in mice fed the supplemented diet. A genetic MTHFR deficiency resulted in neurodegeneration after exposure to in vitro models of stroke, by activating apoptosis promoting p53-dependent mechanisms. These results suggest that one-carbon metabolism plays a significant role in recovery after stroke and MTHFR deficiency contributes to poor recovery from stroke.
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PMID:B-vitamin and choline supplementation increases neuroplasticity and recovery after stroke. 2839 57


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