In the present case-control study, we examined the association between methylenetetrahydrofolate reductase (MTHFR C677T, rs1801133) and methionine synthase (MTRA2756G, rs1805087) polymorphisms and risk for thyroid and breast cancer.
This study aimed to examine the joint effects of folate intake, polymorphisms of 5,10- methylenetetrahydrofolate reductase (MTHFR), methionine synthesis reductase (MTRR) and methionine synthase (MTR) genes and breast cancer risk.
Therefore, DNA methylation related genes, such as methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and DNA methyltransferase (DNMT), together with physical activity and FGFR2, may interact with each other to effect breast cancer risk.
This case-control study found that the MTHFR C677T and MTRA2756G polymorphisms are associated with risk of breast cancer, and folate, vitamin B6, and vitamin B12 intakes influence these associations.
In conclusion, the findings suggest that MTRA2756G polymorphism is not associated with altered susceptibility to breast cancer, while the observed decreased risk in Caucasians, PB subgroup, and large studies and increased risk in small studies may be due to selection bias or other unknown factors.
In this case-control study, we investigated the association between MTHFR C677T and A1298C, TYMS 5'-UTR, MTRA2756G and cSHMT C1420T and also the folate carrier (RFC1 G80A) and breast cancer risk in a northeastern Brazilian population.
This study points out the importance of the interactions between the MTHFR C677T, MTHFR A1298C and MTRA2756G polymorphisms, and also highlights the relevance of the MTRA2756G polymorphism and age in breast cancer risk.
Reduced folate carrier 1 (RFC1) 80A/CYP1A1 m1/CYP1A1 m4 and RFC1 80A/thymidylate synthase (TYMS) 5'-UTR 2R/methionine synthase (MTR) 2756G/COMT 108L genetic combinations were found to inflate breast cancer risk under the conditions of low dietary folate (345 ± 110 vs. 379 ± 139 μg/day) and low plasma folate (6.81 ± 1.25 vs. 7.09 ± 1.26 ng/ml) by increasing plasma 8-oxo-2'-deoxyguanosine (8-oxodG).
We hypothesized that heritable methylation potential might be a risk factor for breast cancer and evaluated possible association with breast cancer for single nucleotide polymorphisms (SNPs) either involving CpG sequences in extended 5'-regulatory regions of candidate genes (ESR1, ESR2, PGR, and SHBG) or CpG and missense coding SNPs in genes involved in methylation (MBD1, MECP2, DNMT1, MGMT, MTHFR, MTR, MTRR, MTHFD1, MTHFD2, BHMT, DCTD, and SLC19A1).
The MTR 2756GG genotype was associated with a higher risk of breast cancer than the 2756AA genotype (OR = 1.99, 95% CI = 1.01-3.92; P trend = 0.801), and statistically significant interactions with regard to risk were observed between the MTHFR A1298C polymorphism and folate (P = 0.024) or vitamin B6 (P = 0.043), and between the MTHFR C677T polymorphism and folate (P = 0.043) or vitamin B12 (P = 0.022).
Neither dietary intake of folate, vitamin B2, vitamin B6, or vitamin B12 nor polymorphisms of MTHFR or MTR genes were significantly associated with breast cancer risk.
Overall, we found no evidence that these common polymorphisms of the MTHFR and MTR genes are associated with promoter methylation of E-cadherin, p16, and RAR-beta2 genes in breast cancer.
Alcohol consumption and genetic variation in methylenetetrahydrofolate reductase and 5-methyltetrahydrofolate-homocysteine methyltransferase in relation to breast cancer risk.
The presence of MTRA2756G mutant allele and MTHFR C677T mutant allele in carriers was associated with increased breast cancer risk [odds ration, 3.2 (P=0.16; 95% confidence interval, 0.76-13.9) and 3.9 (P=0.09; 95% confidence interval, 0.93-16.3), respectively].
Based on the hypothesis that variants of the cSHMT C1420T together with methionine synthase (MS A2756G) and 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) are associated with breast cancer, we performed a multigenic case-control study of the effects to breast cancer risk of four polymorphisms of folate-metabolizing genes against duration of estrogen exposure.
Data suggested an association between a nonsynonymous change in the gene coding for methionine synthase (MTRD919G) and reduced breast cancer risk: OR (95% CI) = 0.84 (0.73-0.96) and 0.85 (0.62-1.15) for heterozygous and homozygote variant genotypes, respectively, compared with common homozygotes; p-trend = 0.01, false discovery rate = 0.14.