Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and FOLFOX response in colorectal cancer patients.
ABSTRACT: WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * Numerous clinical studies, including a few prospective ones, have reported conflicting results on the impact of gene polymorphisms related to fluorouracil (FU) and oxaliplatin pharmacodynamics. WHAT THIS STUDY ADDS: * This prospective study is the first to report that clinical response to FOLFOX is significantly related to methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (677C-->T and 1298A-->C), with a response rate of 37, 53, 63 and 80% in patients harbouring no, one, two or three favourable MTHFR alleles, respectively. * Only polymorphisms of genes related to oxaliplatin pharmacodynamics (GSTpi 105Ile-->Val and XPD 751Ly-->Gln) influenced progression-free survival. * These results corroborate the observation that response was related to the cumulative FU dose, whereas progression-free survival was related to the cumulative oxaliplatin dose. AIMS: To test prospectively the predictive value of germinal gene polymorphisms related to fluorouracil (FU) and oxaliplatin (Oxa) pharmacodynamics on toxicity and responsiveness of colorectal cancer (CRC) patients receiving FOLFOX therapy. METHODS: Advanced CRC patients (n= 117) receiving FOLFOX 7 therapy were enrolled. Gene polymorphisms relevant for FU [thymidylate synthase (TYMS, 28 bp repeats including the G-->C mutation + 6 bp deletion in 3'UTR), methylenetetrahydrofolate reductase (MTHFR, 677C-->T, 1298A-->C), dihydropyrimidine deshydrogenase (IVS14+1G-->A) and Oxa: glutathione S-transferase (GST) pi (105Ile-->Val, 114Ala-->Val), excision repair cross-complementing group 1 (ERCC1) (118AAT-->AAC), ERCC2 (XPD, 751Lys-->Gln) and XRCC1 (399Arg-->Gln)] were determined (blood mononuclear cells). RESULTS: None of the genotypes was predictive of toxicity. Response rate (54.7% complete response + partial response) was related to FU pharmacogenetics, with both 677C-->T (P= 0.042) and 1298A-->C (P= 0.004) MTHFR genotypes linked to clinical response. Importantly, the score of favourable MTHFR alleles (677T and 1298C) was positively linked to response, with response rates of 37.1, 53.3, 62.5 and 80.0% in patients bearing no, one, two or three favourable alleles, respectively (P= 0.040). Polymorphisms of genes related to Oxa pharmacodynamics showed an influence on progression-free survival, with a better outcome in patients bearing GSTpi 105 Val/Val genotype or XPD 751Lys-containing genotype (P= 0.054). CONCLUSIONS: These results show that response to FOLFOX therapy in CRC patients may be driven by MTHFR germinal polymorphisms.
Project description:There is a large degree of variation in tumour response and host toxicities associated with neoadjuvant chemoradiation for rectal cancer patients. We performed a complimentary pharmacogenetic study to investigate germline polymorphisms of genes involved in 5-fluorouracil (5-FU) and irinotecan pathways and their potential association with clinical outcomes and toxicities from neoadjuvant chemoradiation in patients with rectal cancer treated in a prospective genotype-directed study.The germline DNA of 131 patients was genotyped for 10 variants in TYMS, MTHFR, DPYD, UGT1A1, ABCC1 and SLCO1B1 genes. Ninety-six patients were treated with 5-FU/radiotherapy (RT) and 35 received 5-FU/RT/irinotecan. Relationships between genetic variants and adverse events, tumour response, overall and disease-free survivals were assessed.MTHFR 1298A>C and MTHFR diplotypes (for 677C>T and 1298A>C) were associated with chemoradiation-related toxicity when 5-FU was used alone. MTHFR haplotypes (677C-1298C) and diplotypes (CA-TA and TA-TA) showed, respectively, a protective and a negative effect on the incidence of severe diarrhoea or mucositis. No association was observed between genetic markers and drug response.MTHFR polymorphisms can potentially predict toxicity in patients treated with 5-FU as a single chemotherapeutic drug.
Project description:Either oxaliplatin- or irinotecan-containing regimen could receive a good effectiveness in patients with metastatic colorectal cancer as the first-line chemotherapy, but not all patients would benefit from the treatment they have received. This study was to investigate the role of single nucleotide polymorphisms (SNPs) of methylenetetrahydrofolate reductase (MTHFR) and ATP-binding cassette sub-family G member 2 (ABCG2) in selecting the most appropriate treatment for individual patients. Ninety-two metastatic colorectal cancer patients treated with first-line 5-fluoropyrimidine (5-FU), leucovorin, and oxaliplatin (FOLFOX), capecitabine, and oxaliplatin (XELOX) and sixty-two patients receiving 5-FU, leucovorin, and irinotecan (FOLFIRI) were reviewed. The SNPs of MTHFR and ABCG2 were detected using gene sequencing method after DNA PCR amplification, which was extracted from peripheral blood karyocytes. Clinical characteristics and gene polymorphisms were evaluated in univariate and multivariate analysis as predictive factors for response rate (RR) and progression-free survival (PFS). In patients bearing 2-4 genotypes of MTHFR 677C/C, MTHFR 1298 A/C or C/C, ABCG2 34G/G, and ABCG2 421C/A or A/A, those who received oxaliplatin-based chemotherapy achieved a higher RR (41.7 vs. 18.8 %, P = 0.027) and longer median PFS (mPFS) than irinotecan-based therapy [8.9 vs. 7.1 m, FOLFIRI: hazard ratio (HR) = 1.722, 95 % confidence interval (CI) 1.026-2.892, P = 0.040, compared with FOLFOX/XELOX]; on the contrary, patients carrying 0 or 1 above genotype exhibited better outcomes after receiving FOLFIRI chemotherapy (mPFS: 9.3 vs. 6.4 m, FOLFIRI: HR = 0.422, 95 % CI 0.205-0.870, P = 0.019, compared with FOLFOX/XELOX). Combination of SNPs with MTHFR and ABCG2 may play a role in helping clinicians to select first-line chemotherapy for patients with metastatic colorectal cancer.
Project description:Objective: Analysis of the relationship between single nucleotide polymorphisms (SNPs) and outcomes of methotrexate (MTX) therapy for rheumatoid arthritis (RA) in China. Materials and Methods: TYMS 28 bp VNTR (rs34743033), MTHFR [677C>T (rs1801133) and 1298A>C (rs1801131)], ATIC 347C>G (rs2372536), MTR A2756G (rs1805087), and MTRR 66A>G (rs1801394) enzyme proteins may be related to the outcomes of MTX therapy, according to our previous meta-analysis. A total of 162 patients with RA were included in our study. SNPs were evaluated using polymerase chain reaction (PCR). Disease Activity Score 28 (DAS28) was used to evaluate the clinical response, and adverse drug reactions (ADRs) were collected after physical examinations of the patients. Results: The MTHFR 677C>T gene showed a relationship with the ADRs of MTX in the Recessive model [TT vs. (CC+CT)] (p = 0.04, OR = 2.20, 95% CI: 1.01, 4.77). In the Codominant model [CT vs. (CC+TT)], the MTHFR 677C>T gene also showed a trend of association with ADRs (p = 0.08, OR = 0.52, 95% CI: 0.25, 1.08). No significant difference was found between TYMS, MTHFR, ATIC, MTR, and MTRR gene polymorphisms and the RA response or ADRs related to MTX in our study. Conclusion: Our results showed that the MTHFR [677C>T (rs1801133)] TT genotype is associated with ADRs to MTX in Chinese RA patients. Other SNPs, including TYMS 28bp VNTR (rs34743033), MTHFR [677C>T (rs1801133) and 1298A>C (rs1801131)], ATIC 347C>G (rs2372536), MTR A2756G (rs1805087), and MTRR 66A>G (rs1801394) gene polymorphisms, were not associated with MTX treatment outcomes. Further studies are required to validate these findings.
Project description:Primary Sjogren's syndrome (pSS) confers increased risk for non-Hodgkin lymphoma (NHL) development. Two common polymorphisms, the c. 677C?>?T and c. 1298A?>?C, of the methylene-tetrahydrofolate reductase (MTHFR) gene, an enzyme essential in DNA synthesis and methylation, have been associated with susceptibility to NHL. Herein, we tested the hypothesis that MTHFR variants contribute to pSS-related lymphomagenesis. 356 pSS patients, of whom 75 had MALT and 19 non-MALT NHL and 600 healthy controls were genotyped for the detection of MTHFR polymorphisms. DNA methylation levels were assessed by pyrosequencing of the LINE-1 retroelement promoter in DNA from 55 salivary gland tissues from pSS patients. DNA double-strand breaks were determined in peripheral blood mononuclear cells from 13 pSS patients, using comet assay. ?nalysis according to lymphoma subtype revealed increased frequency of c. 677C?>?T TT genotype and T allele, as well as reduced prevalence of the c. 1298A?>?C C allele in the pSS non-MALT group compared to controls and patients without NHL. MTHFR c. 677C?>?T TT genotype was associated with reduced DNA methylation levels, while MTHFR c. 1298A?>?C AC genotype with reduced DNA double-strand breaks levels. MTHFR variants may be involved in SS non-MALT NHL development, through contribution to defective DNA methylation and genomic instability.
Project description:BACKGROUND: Non-syndromic cleft lip with or without cleft palate (nsCL/P) is one of the most common congenital abnormalities of the orofacial region with a multifactorial etiology. The present study aimed to investigate the association of two common polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene (c.677C>T and c.1298A>C) with the occurrence of nsCL/P in an Iranian population. METHODS: Forty-five nsCL/P patients, 43 mothers of patients, and 101 unrelated controls participated in the present study. Analysis of c.677C>T and c.1298A>C polymorphisms in MTHFR gene was conducted using polymerase chain reaction and restriction enzyme digestions. RESULTS: There was no statistical difference in genotype and allele frequencies for c.677C>T variants between patients or their mothers and the control group. However, differences in the frequencies of alleles and genotypes of c.1298A>C polymorphism were statistically significant between patients and control group (P=0.01 for alleles and P=0.005 for genotypes). The odds ratios (OR) for the CC versus AA homozygotes were 6.1 (95% CI 1.8-20.5) and 4.2 (95% CI 1.1-15.4), in patients and mothers, respectively. CONCLUSIONS: We found no association between genetic polymorphism of MTHFR c.677C>T and the risk of nsCL/P in the population studied. Yet the results suggested that c.1298A>C polymorphism of MTHFR gene may be a risk factor for the occurrence of nsCL/P in the Iranian population.
Project description:Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T.We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autologous vein reconstruction for arterial occlusive disease as controls. We compared the frequencies of c.677C>T and another polymorphism of MTHFR, c.1298A>C, with morphology and types of complicated disease. Morphology was recorded as a trunk or perforator type and peripheral congestive complication was defined as chronic venous insufficiency (CEAP C3-6) associated with edema and skin manifestations.Multivariate analysis of genotypes for c.677C>T and c.1298A>C indicated that c.677C>T was associated significantly with the trunk phenotype (43/53 patients, 81%, p < 0.01), while c.1298A>C was associated significantly with the perforator phenotype (18/24 patients, 75%, p < 0.01) of primary varicose veins. Accordingly, when both c.677C>T and c.1298A>C displayed a heterozygous genotype, the patients were more likely to present with both phenotypes. Additionally, c.1298A>C was found to be strongly linked to the congestive complication (34/51 patients, 67%, p < 0.01).Both polymorphisms of MTHFR may be involved in the morphological specification of primary varicose veins and contribute to the development of complicated disease.None.
Project description:Aim: Variants of the MTHFR gene have been associated with a wide range of diseases. Materials & methods: The present study analyzed data from clinical genotyping of MTHFR 677C>T and 1298A>C in 1405 patients in urban primary care settings. Results: Striking differences in ethnogeographic frequencies of MTHFR polymorphisms were observed. African-Americans appear to be protected from MTHFR deficiency. Hispanics and Caucasians may be at elevated risk due to increased frequencies of 677C>T and 1298A>C, respectively. Conclusion: Individuals carrying mutations for both genes were rare and doubly homozygous mutants were absent, suggesting the TTcc is extremely rare in the greater population. The results suggest multilocus MTHFR genotyping may yield deeper insight into the ethnogeographic association between MTHFR variants and disease.
Project description:Background:The gene for 5,10-methylenetetrahydrofolate reductase (NAD(P)H) or MTHFR gene encodes protein methylenetetrahydrofolate reductase (MTHFR), an enzyme important in folate metabolism. Aim:The aim of this study was to determine the frequencies of 677C>T and 1298A>C polymorphisms in the MTHFR gene of healthy subjects from the population. Material and methods:The blood samples were collected from 164 unrelated and healthy donors from population consisted of 98 females and 66 males. Both the MTHFR 677C>T and 1298A>C single nucleotide polymorphisms (SNPs) were analyzed by Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Linkage disequilibrium (LD) between pair of SNPs was calculated through Haploview analysis. Results:The frequency of MTHFR 677T allele in the population (32.62%) was in agreement with the frequency of this allele in most other populations, however, the frequency of MTHFR 1298C allele (38.41%) was higher than that reported for most other populations in the world. Haploview analysis showed a relatively strong LD between 677C>T and 1298A>C SNPs with D' values of 0.87. Conclusion:Regarding the two MTHFR polymorphisms, three of the nine combined genotypes were present in 87.2% of the population. 33.54% subjects were complex heterozygous (677CT/1298AC genotype), 34.15% subjects had 677CC/1298AC and 19.51% of 677CT/1298AA genotype. The subjects with 677TT genotype had a 1298AA or 1298AC genotype while subjects with 1298CC genotype had only 677CC genotype. The subjects with 677CC/1298AA genotype were only 3.05%. We were not found triple 677CT/1298CC and quadruple 677TT/1298CC mutation suggesting decreased viability of embryos with increased numbers of mutant alleles.
Project description:BACKGROUND: The polymorphism 5,10-methylenetetrahydrofolate reductase (MTHFR) c.1298A>C is associated with various diseases. 45 DNA samples homozygous for the A allele and 40 DNA probes homozygous for the C allele were taken from healthy German subjects of white Caucasian origin to analyze the haplotype of the two MTHFR c.1298A>C alleles. Samples were genotyped for the polymorphism MTHFR c.677C>T and for the silent polymorphisms MTHFR c.129C>T, IVS2 533 G>A, c.1068C>T and IVS10 262C>G. FINDINGS: Haplotype construction revealed that the C-allele of MTHFR c.1298A>C was more frequently observed in cis with c.129T, IVS2 533A, c.677C, c.1068T, and IVS10 262 G than expected from normal distribution. Estimation of the most recent common ancestor with the DMLE + 2.3 program resulted in an estimated age of approximately 36,660 years of the MTHFR c.1298C allele. CONCLUSION: Given that the era from 30,000 to 40,000 years ago is characterised by the spread of modern humans in Europe and that the prevalence of the MTHFR c.1298C allele is significantly higher in Central Europe in comparison to African populations, a selective advantage of MTHFR c.1298C could be assumed, e. g. by adaption to changes in the nutritional environment. The known founder ancestry of the T allele of MTHFR c.677C>T allele, together with the present data suggests that the MTHFR mutant alleles c.677T and 1298C arose from two independent ancestral alleles, that both confer a selective advantage.
Project description:Fluoropyrimidine-based chemotherapy is extensively used for the treatment of solid cancers, including colorectal cancer. However, fluoropyrimidine-driven toxicities are a major problem in the management of the disease. The grade and type of the toxicities depend on demographic factors, but substantial inter-individual variation in fluoropyrimidine-related toxicity is partly explained by genetic factors. The aim of this study was to investigate the effect of dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), and methylenetetrahydrofolate reductase (MTHFR) polymorphisms in colorectal cancer patients. Eighty-five patients who were administered fluoropyrimidine-based treatment were included in the study. The DPYD, TYMS and MTHFR polymorphisms were scanned by a next generation Sequenom MassARRAY. Fluoropyrimidine toxicities were observed in 92% of all patients. The following polymorphisms were detected: DPYD 85T>C (29.4% heterozygote mutants, 7.1% homozygote mutants), DPYD IVS 14+1G>A (1.2% heterozygote mutants), TYMS 1494del TTAAAG (38.4% heterozygote mutants, 24.7% homozygote mutants), MTHFR 677C>T (43.5% heterozygote mutants, 9.4% homozygote mutants) and MTHFR 1298A>C (8.2% heterozygote mutants, 2.4% homozygote mutants). A statistically significant association was demonstrated between MTHFR 677C>T and fluoropyrimidine-related toxicity. Furthermore, MTHFR 1298A>C was associated with hematopoietic toxicity. MTHFR polymorphisms may be considered as related factors of fluoropyrimidine toxicity and may be useful as predictive biomarkers for the determination of the colorectal cancer patients who can receive the greatest benefit from fluoropyrimidine-based treatments.