Association of MTHFR C677T variant genotype with serum folate and Vit B12 in Iranian patients with colorectal cancer or adenomatous polyps

Meta Analysis of Methylenetetrahydrofolate Reductase (MTHFR) C677T polymorphism and its association with folate and colorectal cancer

BACKGROUND

DNA hypomethylation and uracil misincorporation into DNA, both of which have a very important correlation with colorectal carcinogenesis. Folate plays a crucial role in DNA synthesis, acting as a coenzyme in one-carbon metabolism, which involves the synthesis of purines, pyrimidines, and methyl groups. MTHFR, a key enzyme in folate metabolism, has been widely studied in relation to neural tube defects and hypertension, but its role in colorectal cancer remains underexplored. Therefore, understanding the role of folate and MTHFR genes in colorectal cancer may be helpful for potential preventive or therapeutic interventions. In this meta-analysis, the effects of MTHFR genotype and folate intake on colorectal cancer incidence were analyzed.

METHODS

We searched PubMed,Embase, Web of Science, and CNKI database to identify relevant studies up to January 2024. We included a series of studies on the association of MTHFR C677T genotype and folate intake with colorectal cancer incidence. The meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). It included 100 studies (39702 cases and 55718 controls),that investigated the association between the MTHFR C677T polymorphism and colorectal cancer (CRC). Additionally, the analysis incorporated further stratification by ethnic population and geographical region. Furthermore, Six of the studies which clarified high amount of folate might be a protective factor for CRC in all three MTHFR C677T genotype, especially in TT genotype.

RESULTS

MTHFR 677TT genotype was negatively associated with CRC incidence compared with CC genotype (OR = 0.89; 95% CI: 0.85-0.93; P < 0.00001; Z = 5.17). MTHFR 677CT genotype was not significantly associated with colorectal cancer incidence (OR = 1.00; 95% CI: 0.98,1.03). A negative correlation between TT genotype and CRC was observed in ethnics of Asians (OR = 0.83, 95% CI: 0.76, 0.91), Caucasians (OR = 0.93, 95% CI: 0.88, 0.99) and the region of USA (OR = 0.77, 95% CI: 0.71, 0.85), Asia (OR = 0.93, 95% CI: 0.86, 1.00) and Europe (OR = 0.93, 95% CI:0.87, 1.00),but not in Indian (TT: OR = 1.67, 95% CI: 1.06, 2.63; CT: OR = 1.31, 95% CI: 1.00, 1.73)). Amount folate intakes might reduce the morbidity of CRC for people in MTHFR 677TT genotype (OR = 0.68; 95% CI: 0.48,0.96; P = 0.03).

CONCLUSION

The analysis showed that the incidence of colorectal cancer was reduced among individuals with TT genotype. The individuals with TT genotype and amount folate intake may collectively improve the incidence of colorectal cancer. While the MTHFR 677TT genotype is associated with a reduced risk of CRC, especially in certain populations, these findings should be interpreted with caution due to the limitations of retrospective studies.

Impacts of Methylenetetrahydrofolate Reductase Genotypes on Hallux Valgus

BACKGROUND/AIM

Hallux valgus (HV) is the most common deformity of the forefoot. Although HV has been strongly associated with a family history, its genetic underpinnings remain unclear. Few studies have examined the relationship between folic acid metabolism, which is critical in normal bone development, and HV. The study aimed to investigate the contribution of methylenetetrahydrofolate reductase (MTHFR) genotypes to the risk of HV.

MATERIALS AND METHODS

The MTHFR rs1801133 and rs1801131 genotypes were analyzed in 150 patients with HV and 600 controls without HV, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The results highlighted a significant difference in the genotypic frequency distributions of MTHFR rs1801133 between the HV cases and non-HV controls (p for trend=0.0024). Specifically, individuals with the homozygous TT genotype at MTHFR rs1801133 exhibited a 2.57-fold increased risk of HV (95% confidence interval=1.49-4.42, p=0.0009). However, those with the CT genotype did not show an elevated risk. Stratified analysis showed no correlation between MTHFR rs1801133 genotypic distributions and different age groups (below or above 51 years) or sex (both p>0.05). Furthermore, no associations were identified between MTHFR rs1801133 and height, weight, or body mass index in relation to HV risk.

CONCLUSION

The TT genotype of MTHFR rs1801133 is associated with an increased risk of HV. Subgrouping HV patients based on their MTHFR genotypes and related comorbidities, such as rheumatoid arthritis, may offer a new approach to diagnosis.

Standardization and application of ARMS TaqMan real-time PCR for screening of folate metabolism genes in Han Chinese

Folate has antioxidant properties, and low concentration in seminal plasma may be associated with increased DNA damage in sperm. Mutations of the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes, including MTHFR C677T (rs1801133), MTHFR A1298C (rs1801131), and MTRR A66G (rs1801394), can lead to decreased activity of the encoded folate metabolic enzymes, thereby affecting male reproduction. The current SNP detection methods commonly used in clinical practice have some shortcomings, such as long time-consuming, complex detection steps, or high cost. The purpose of this study was to establish a simple, time-saving, sensitive, accurate, and easy to clinical popularization method for folate metabolism gene detection. We combined ARMS-PCR with TaqMan fluorescent probe to establish an ARMS TaqMan real-time PCR detection method. According to the variation of rs1801131, rs1801133, and rs1801394, two specific primers (one wild type and one mutant) were designed. Mismatched nucleotides were introduced at the penultimate or third position to improve the specificity of the primer. Specific TaqMan probe was introduced to detect PCR products to improve the sensitivity of the method. The results showed that the sensitivity of ARMS TaqMan real-time PCR in SNP genotyping was 1 ng, and the accuracy was 100%. A total of 249 clinical samples were detected by the established method, and the correlation between three SNPs and semen quality was analyzed. We found that individuals carrying the AG + GG genotype of rs1801394 had a lower risk of abnormal semen quality. In conclusion, we developed a highly sensitive, accurate, rapid, and easy to be popularized method for detecting SNPs of rs1801394, rs1801131, and rs1801133. ARMS TaqMan real-time PCR is a reliable SNP genotyping method in folate metabolism genes.

Association of Methylenetetrahydrofolate Reductase rs1801133 Gene Polymorphism with Cancer Risk and Septin 9 Methylation in Patients with Colorectal Cancer

PURPOSE

Colorectal cancer (CRC) is one of the most common malignancies, with a high incidence and mortality worldwide. Methylated Septin 9 (mSEPT9) has been used clinically as an auxiliary tool for CRC screening. The aim of the present study was to investigate the association of the methylenetetrahydrofolate reductase (MTHFR) rs1801133 polymorphism with the risk of CRC and the methylation status of Septin 9 in CRC.

METHODS

Information of 540 patients with a confirmed diagnosis of CRC and with a physical examination were utilized to assess the association of the MTHFR rs1801133 polymorphism with CRC and the methylation of SEPT9. MTHFR rs1801133 polymorphism was genotyped using polymerase chain reaction (PCR). The commercial Septin 9 Gene Methylation(mSEPT9) Detection Kit was used for plasma SEPT9 methylation analysis.

RESULTS

Among 540 patients, 61.48% were men and the median age was 54.47 ± 13.14. 65.37% of all colorectal tumors developed in the rectum. 195 patients had negative mSEPT9 methylation, while 345 had positive results. 87 individuals with stage I, 90 with stage II, 287 with stage III, and 76 with stage IV colorectal cancer were included in the sample. The results demonstrated that the positivity rate and degree of methylation of mSEPT9 were remarkably higher in patients with more advanced TNM stages than in those with less advanced stages. The frequencies of the MTHFR rs1801133 CC genotype and allele C carriers in patients with CRC were significantly higher than those in healthy individuals (P = 0.006 and P = 0.001, respectively). The positivity rate of the mSEPT9 assay was significantly higher among the MTHFR rs1801133 TT genotype and allele T carriers than among the CC and allele C carriers respectively. The MTHFR rs1801133 TT genotype and allele T carriers were positively associated with the methylation of SEPT9 (OR = 3.320, 95% CI 1.485-7.424, P = 0.003 and OR = 1.783, 95% CI 1.056-3.010, P = 0.030, respectively).

CONCLUSION

In conclusion, individuals harboring the MTHFR rs1801133 CC genotype had a higher risk of CRC and the MTHFR rs1801133 TT carriers were more susceptible to Septin 9 gene methylation.

The Role of Single-Nucleotide Polymorphisms in Cholangiocarcinoma: A Systematic Review

Single-nucleotide polymorphisms (SNPs) play an essential role in various malignancies, but their role in cholangiocarcinoma (CCA) remains to be elucidated. Therefore, the purpose of this systematic review was to evaluate the association between SNPs and CCA, focusing on tumorigenesis and prognosis. A systematic literature search was carried out using PubMed, Embase, Web of Science and the Cochrane database for the association between SNPs and CCA, including literature published between January 2000 and April 2022. This systematic review compiles 43 SNPs in 32 genes associated with CCA risk, metastatic progression and overall prognosis based on 34 studies. Susceptibility to CCA was associated with SNPs in genes related to inflammation (PTGS2/COX2, IL6, IFNG/IFN-γ, TNF/TNF-α), DNA repair (ERCC1, MTHFR, MUTYH, XRCC1, OGG1), detoxification (NAT1, NAT2 and ABCC2), enzymes (SERPINA1, GSTO1, APOBEC3A, APOBEC3B), RNA (HOTAIR) and membrane-based proteins (EGFR, GAB1, KLRK1/NKG2D). Overall oncological prognosis was also related to SNPs in eight genes (GNB3, NFE2L2/NRF2, GALNT14, EGFR, XRCC1, EZH2, GNAS, CXCR1). Our findings indicate that multiple SNPs play different roles at various stages of CCA and might serve as biomarkers guiding treatment and allowing oncological risk assessment. Considering the differences in SNP detection methods, patient ethnicity and corresponding environmental factors, more large-scale multicentric investigations are needed to fully determine the potential of SNP analysis for CCA susceptibility prediction and prognostication.

The Roles of MTRR and MTHFR Gene Polymorphisms in Colorectal Cancer Survival

BACKGROUND

Paradoxically epidemiological data illustrate a negative relationship between dietary folate intake and colorectal cancer (CRC) risk. The occurrence and progression of CRC may be influenced by variants in some key enzyme coding genes in the folate metabolic pathway. We investigated the correlation between genetic variants in methionine synthase reductase (MTRR) and methylenetetrahydrofolate reductase (MTHFR) and CRC survival.

METHODS

This study used data collected from the Newfoundland Familial Colorectal Cancer Study. A total of 532 patients diagnosed with CRC for the first time from 1999 to 2003 were enrolled, and their mortality were tracked until April 2010. DNA samples were genotyped by Illumina's integrated quantum 1 million chip. Cox models were established to assess 33 tag single-nucleotide polymorphisms in MTRR and MTHFR in relation to overall survival (OS), disease-free survival (DFS) and CRC-specific survival.

RESULTS

The MTRR and MTHFR genes were associated with DFS and CRC-specific survival in CRC patients at the gene level. After multiple comparison adjustment, MTRR rs1801394 A (vs. G) allele was associated with increased DFS (p = 0.024), while MTHRT rs3737966 (G vs. A), rs4846049 (T vs. G), rs1476413 (A vs. G), rs1801131 (C vs. A), rs12121543 (A vs. C), rs1801133 (C vs. T), rs4846052 (T vs. C), rs2066471 (A vs. G) and rs7533315 (T vs. C) were related to worse CRC-specific survival. Additionally, significant interactions were seen among pre-diagnostic alcohol consumption with MTRR rs1801394, rs3776467, rs326124, rs162040, and rs3776455, with superior OS associated with those protective variant alleles limited to patients with alcohol consumption under the median. The MTHFR rs3737966 (G vs. A) allele seemed to be detrimental to CRC survival only among subjects with fruit intake below the median.

CONCLUSIONS

Polymorphic variants in MTRR and MTHFR genes that code for key enzymes for folate metabolism may be associated with survival in patients with CRC. The gene-CRC outcome association seems modulated by alcohol drinking and fruit intake.