• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3163-3168
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• 2013

Methylenetetrahydrofolate reductase (MTHFR) plays a central role in folate metabolism. This study with 381 esophageal cancer patients and 432 healthy controls was conducted to examine the association of MTHFR C677T and A1298C polymorphisms with susceptibility to esophageal cancer (EC) in a Chinese population. Compared with the CC genotype of MTHFR C677T, subjects carrying homozygote TT and variant genotypes (CT+TT) demonstrated reduced risk of EC with adjusted ORs (95% CI) of 0.44 (0.28-0.71) and 0.57 (0.37-0.88), respectively. However, no association was found between the MTHFR A1298C polymorphism and the risk of EC. Comparing to haplotype CA, haplotypes TA and TC could reduce the susceptibility to EC with adjusted ORs (95% CI) of 0.61(0.47-0.79) and 0.06 (0.01-0.43), respectively. In conclusion, the present study suggested that the MTHFR C677T polymorphism can markedly influence the risk of EC in Chinese.

• BMB Reports
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• v.37 no.2
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• pp.234-238
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• 2004

This study was designed to investigate, in the Turkish population, the association of methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism and left ventricular hypertrophy (LVH) in patients with type II diabetes mellitus. Our study included 249 patients with type II diabetes mellitus (102 men, 147 women) and 214 healthy volunteers as controls (91 men, 123 women). MTHFR C677T genotypes were determined by polymerase chain reaction, restriction fragment length polymorphism techniques. No differences were observed in the distribution of MTHFR genotypes or allele frequencies in the cases versus the controls. The frequency of the MTHFR-mutated allele (T) was 31.7% in the type II diabetes mellitus versus 31.1% of the controls. The homozygous mutation (T/T) in the MTHFR gene was identified in 12% of the type II diabetes mellitus versus 9.3% of the controls. Patients with the TT genotype showed a higher prevalence of LVH when compared to patients with the CC and CT genotypes (p = 0.01). The MTHFR gene C677T mutation may be a possible risk factor for the development of LVH in the type II diabetic patients.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.168-173
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• 2011

Objective: To examine the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and hyperhomocysteinemia in women with unexplained recurrent miscarriages (RM) and to investigate the association between MTHFR genotype variants and alloimmune activation, proportion of peripheral blood natural killer (pbNK) cells. Methods: A total of 39 patients with a history of two or more unexplained miscarriages were recruited to this study. The controls were women who had a live birth without a history of RM (n=50). The proportion of pbNK cells was measured by flow cytometry. Plasma homocysteine levels and the incidence of the MTHFR variant of the RM and control groups were compared. The proportion of pbNK cells was compared to the MTHFR variants in the RM group. Results: No differences were found between the two groups' mean plasma homocysteine levels ($7.6{\pm}1.5{\mu}mol$/L vs. $7.1{\pm}2.1{\mu}mol$/L) or incidence of the MTHFR genotype variant (CC, 35% vs. 33%; CT, 40% vs. 53%; and TT, 25% vs. 14%). In the RM group, individuals with the TT variant ($7.7{\pm}1.1{\mu}mol$/L) had higher homocysteine levels than those with the CC and CT variants ($7.4{\pm}1.9{\mu}mol$/L and $7.4{\pm}1.2{\mu}mol$/L) and those with the CT variant ($19.2{\pm}8.1%$) had a higher proportion of CD3-/CD56+ pbNK cells than those with the CC and TT variants ($17.7{\pm}6.6%$ and $17.9{\pm}7.0%$), but the results of both comparisons were statistically insignificant. Conclusion: These preliminary results show no difference in plasma homocysteine levels between the RM and control groups or among MTHFR genotype variants in the RM group, which may suggest that the plasma homocysteine level is difficult to use as a predictive marker of RM in the Korean population. A study of a larger number of patients is needed.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.3
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• pp.183-190
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• 2004

Objectives: Methylenetetrahydrofolate reductase (MTHFR) mutation are commonly associated with hyperhomocysteinemia, and through their defects in homocysteine metabolism, they have been implicated as a risk factor for recurrent spontaneous abortion. Recent report describe that 28-bp tandem repeat polymorphism in thymidylate synthase enhancer region (TSER) that influence enzyme activity would affect plasma homocysteine level. We have investigated the relationship between TSER genotype and plasma homocysteine level in 54 patients with recurrent spontaneous abortion. Methods: Plasma homocysteine level was measured by fluorescent polarizing immunoassay. MTHFR mutation (C677T and A1298C) was identified by PCR-restriction fragment length polymorphism assay and TSER mutation was analyzed by PCR method. The data were analyzed using the program SAS 8.2 for Windows. Results: Total homocysteine level was significantly higher in MTHFR 677TT genotype ($9.80{\pm}3.87{\mu}mol/L$) than MTHFR 677CC genotype ($8.14{\pm}1.74{\mu}mol/L$) in Korean patients with unexplained recurrent spontaneous abortion (p=0.0143). However, the plasma homocysteine level was not significantly different in the MTHFR 1298AA ($8.42{\pm}2.65{\mu}mol/L$) and 1298CC ($6.09{\pm}0.32{\mu}mol/L$; p=0.2058) and, TSER 2R2R ($8.61{\pm}1.68{\mu}mol/L$) and 3R3R ($8.05{\pm}2.81{\mu}mol/L$; p=0.9319) mutant genotypes, respectively. In this study, we found the combination effects of TSER and MTHFR C677T genotypes. Plasma homocysteine levels were the highest ($11.47{\pm}4.66{\mu}mol/L$) in individuals with TSER 3R3R ($8.05{\pm}2.81{\mu}mol/L$) and MTHFR 677TT ($9.80{\pm}3.87{\mu}mol/L$) genotypes. Individuals with a combination of both TSER 2R2R/2R3R and MTHFR 677CC/CT genotypes ($7.69{\pm}1.77{\mu}mol/L$) had lower plasma homocysteine levels than TSER 2R2R ($8.61{\pm}1.68{\mu}mol/L$) and MTHR 677CC ($8.14{\pm}1.74{\mu}mol/L$) genotypes, respectively. The effect of MTHFR polymorphism in the homocysteine metabolism appears to be stronger than that of TSER polymorphism. Conclusion: Although statistically not significant, we found the elevated level of plasma homocysteine in combined genotypes with TSER and MTHFR (C677T and A1298C) in Korean patients with unexplained habitual abortion. In this study, we reported the possibility that TSER polymorphism is a genetic determinant of plasma homocysteine levels in the Korean patients as well as MTHFR C677T polymorphism. A large prospective study is needed to verify our findings.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1599-1603
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• 2012

Objectives: Since methylenetetrahydrofolate reductase (MTHFR) maintains the balance of circulating folate and methionine and blocks the formation of homocysteine, its regulation in relation to different cancers has extensively been studied in different populations. However, information on Pakistani breast cancer patients is lacking. The MTHFR gene has two most common mutations that are single nucleotide additions which result in change of amino acids C677T to Ala222val and A1298C to Glu429Ala. Methodology: 110 sporadic breast patients with no prior family history of cancer or any other type of genetic disorders along with 110 normal individuals were screened for mutations in exons 1 to exon 9 using single strand conformational polymorphism, RFLP and sequencing analyzer. Results: The p values for the 677CC, 677CT, and 677TT genotypes were 0.223, 0.006, and 0.077, respectively. Those for the 1298AA, 1298AC, and 1298CC genotypes were 0.555, 0.009, and 0.003, respectively. Conclusions: We found an overall a significant, weak inverse association between breast cancer risk and the 677TT genotype and an inverse association with the 1298C variant. These results for MTHFR polymorphism might be population specific in sporadic breast cancer affected patients but many other factors need to be excluded before making final conclusions including folate intake, population and disease heterogeneity.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5853-5860
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• 2014

Background: Methylenetetrahydrofolate (MTHFR) is the key enzyme of the folate metabolic pathway and several studies have pointed to association between the MTHFR C677T polymorphism and breast cancer risk. Although significant association was observed in some studies, in others no clear link could be established. Objective: A meta-analysis of published Asian case control studies was therefor carried out to shed further light on any C677T breast cancer association. Materials and Methods: PubMed, Springer Link, Google Scholar and Elsevier databases were searched for case control studies of associations between MTHFR C677T polymorphism and breast cancer risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association. A total of 36 studies including 8,040 cases and 10,008 controls were included in the present meta-analysis. Results: Overall, a significantly elevated breast cancer risk was associated with the T allele and TT genotype in homozygote comparison and dominant genetic models when all studies were pooled into the meta-analysis (T vs C (allele contrast model): OR=1,23, 95%CI=1.13-1.37, p=0.000 ; TT vs CC(homozygote model): OR=1.38, 95%CI=1.16-1.63, p=0.0003; TT+CT vs CC (dominant model): OR=1.12, 95%CI=1.01-1.23, p=0.02). Conclusions: The present meta-analysis strongly suggested a significant association between the MTHFR C677T polymorphism and risk of breast cancer in Asian populations.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.1
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• pp.61-61
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• 2006

Objectives : This study was performed to understand the influence of the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) genotypes on the spontaneously aborted embryos. Methods : DNA was extracted from tissue samples of 95 spontaneously aborted embryos and 100 samples of normal children randomly and 449 samples of normal adults were selected as the controls. MTHFR genotypes were determined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Results : The aborted embryo group had higher frequency of MTHFR 677CC type (p=0.014) and lower 677CT type (p=0.063) than the controlled child group. The frequency of MTHFR 677CT type was drastically lower than that of controlled adult group (p=0.032). In the MTHFR C677T/A1298C combination, 677CC/1298AC genotype of the aborted embryo was significantly higher (p=0.034) than that of controlled child group, but it was not statistically significant in controlled adult group (p=0.063). Conclusion : MTHFR 677CC and MTHFR 677CC/1298AC genotypes may represent genetic markers for the risk of spontaneously aborted embryos at least in Koreans.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5069-5074
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• 2012

Objectives: The purpose of this study was to determine the relationship between methylation status of the Dact1 gene and MTHFR a1298c polymorphic forms in transitional cell carcinoma tissues in a Chinese population. Methods: Polymorphisms of folate metabolism enzyme gene MTHFR were assessed by restrictive fragment length polymorphism (RFLP) methods and PCR-based DNA methylation analysis was used to determine the CpG island methylation status of the Dact1 gene. Associations between the methylation status of the Dact1 gene and clinical characteristics, as well as MTHFR a1298c polymorphisms, were analyzed. Results: aberrant methylation of the Dact1 gene was found in 68.3% of cancer tissues and 12.4% of normal tissues,. The methylation rate of the Dact1 gene in cancer tissues was significantly higher in patients with lymph node metastasis than in those without lymph node metastasis (46.3% vs. 17.2%, P = 0.018). No association was found between aberrant DNA methylation and selected factors including sex, age, tobacco smoking, alcohol consumption and green tea consumption. After adjusting for potential confounding variables, variant allele of MTHFR a1298c was found to be associated with methylation of the Dact1 gene. Compared with wild type CC, the odds ratio was 4.33 (95% CI: 1.06-10.59) for AC and 4.95 (95% CI: 1.18-12.74) for AA. The N stage in TNM staging and the occurrence of lymph node metastasis were associated with an MTHFR 1298 AA+AC genotype (P<0.05). Conclusion: MTHFR 1298 AC and AA genotypes might help maintain a normal methylation status of the Dact1 gene, aberrant CpG island methylation of which is closely related to the genesis and progression of transitional cell carcinoma.

• Nutritional Sciences
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• v.9 no.1
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• pp.35-41
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• 2006

It should be concerned to the women with mutated genotype of methylenetetrahydrofolate reductase (MTHFR), C677T or A1298C, since they need more folate than those with wild genotypes. In this study, we evaluated the folate status of Korean women of childbearing age according to their MTHFR polymorpiysm. Dietary folate intakes, plasma and erythrocyte folate concentrations, plasma homocysteine concentrations, and urinary excretions of para-aminobenzoylglutamate (pABG) and para-acetoamidobenzoylglutamate (ApABG) of twenty-five subjects aged between 19 and 35 years old were determined Folate intakes seemed to be inadequate, being only three-quarters of the Korean RDA of folate. More than one-quarter of the subjects was exposed to folate deficiency risk as determined by erythrocyte folate concentration and almost one-quarter of the subjects showed hyperhomocysteinemia, although they had normal plasma folate concentrations. Urinary excretions of pABG and ApABG seemed to be low and ApABG constituted more than $85\%$ of total folate catabolites. There were no significant differences in dietary folate intakes, plasma concentrations of folate and homocysteine, and urinary excretions of pABG and ApABG among the geneotypes of both C677T and A1298C. However, the subjects with 1298AC genotype had significantly lower erythrocyte folate concentration than those with 1298AA. Erythrocyte folate concentration showed an inverse relationship with plasma homocysteine concentration and positive relationships with urinary excretions of pABG and ApABG. The results of this study imply that mutations of 677C$\rightarrow$T and 1298A$\rightarrow$C in the study were not associated with decreased plasma folate and raised plasma homocysteine concentrations. A1298C polymorphism night be, however, more influential on erythrocyte folate concentration than C677T polymorphism, and urinary excretions of folate catabolites, pABG and ApABG, might be reliable indexes of folate nutritional status like plasma homocysteine concentrations.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5007-5011
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• 2015

Background: Breast cancer is a major cause of morbidity and mortality in Jordan and worldwide. Abnormality of DNA methylation is a possible mechanism for the development of cancer. Methylenetetrahydrofolate reductase (MTHFR) is involved in DNA methylation. Our aim was to study the association between genetic polymorphisms of MTHFR at two sites (C677T and A1298C) and their haplotypes and the risk of breast cancer among Jordanian females. Materials and Methods: A case-control study involving 150 breast cancer cases and 150 controls was conducted. Controls were age-matched to cases. Polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) technique and sequencing were conducted to determine the genotypes. Results: There was a significant difference in genotype frequency of C677T in the 41-60 year age category [cases: CC (37.4%), CT (49.5%) and TT (13.2%); controls: CC (56.3%), CT (35.6%) and TT (8%), p= 0.04; $OR_{TT\;vs.\;CC}$: 2.5, 95% CI: (0.9-6.9); $OR_{at\;least\;on\;T$: 2.1, 95%CI: (1.2-3.9)]. There was no significant difference in genotype frequency of A1298C between cases and controls [cases: AA (46.6%), AC (41.8%) and CC (11.6%); controls: AA (43%), AC (47.4%) and CC (9.6%); p= 0.6]. There was a significant difference of MTHFR genetic polymorphism haplotypes among breast cancer cases and controls [cases/control: CA: 38.3/45.4%; CC: 28.9/25.2%; TA: 29.2/21; TC: 3.6/8.3; p value= 0.01; $OR_{TA\;vs.\;CA}=1.6$; 95% CI (1.1-2.5); p= 0.02]. Conclusions: Genetic polymorphism of MTHFR C677T may modulate the risk of breast cancer especially in the 41-60 year age group. Additionally, TA haplotype amends the risk of breast cancer. Future studies with a larger sample size are needed to validate the role of MTHFR genetic polymorphisms in breast cancer.