Associations between MTHFR gene polymorphisms (C677T and A1298C) and genetic susceptibility to prostate cancer: a systematic review and meta-analysis.

Background: The association between MTHFR gene polymorphisms (C677T and A1298C) and prostate cancer risk remains controversial. Methods: Two independent researchers searched the PubMed, Embase, Cochrane and Web of Science databases for all papers published up to 12/19/2023 and used various genetic models to evaluate the relationship between MTHFR polymorphisms and prostate cancer risk. Results: The meta-analysis included 26 case‒control studies with a total of 12,455 cases and 13,900 controls with the C677T polymorphism and 6,396 cases and 8,913 controls with the A1298C polymorphism. Overall, no significant association was found between the MTHFR gene polymorphisms and prostate cancer risk. However, the C677T polymorphism was associated with reduced prostate cancer risk in the Asian population (T allele vs. C allele: OR = 0.759, 95% CI 0.669-0.861, p < 0.001; TT + CT vs. CC: OR = 0.720, 95% CI 0.638-0.812, p < 0.001; TT vs. CC + CT: OR = 0.719, 95% CI 0.617-0.838, p < 0.001; TT vs. CC: OR = 0.620, 95% CI 0.522-0.737, p < 0.001); however, the A1298C polymorphism was associated with an increased risk in the mixed race group from the United States (CC + AC vs. AA: OR = 1.464, 95% CI 1.052-2.037, p = 0.024; AC vs. AA: OR = 1.615, 95% CI 1.037-2.514, p = 0.034). Conclusion: The meta-analysis suggested that MTHFR gene polymorphisms (C677T and A1298C) may have different effects on prostate cancer risk in specific populations.

The protective effects of the methylenetetrahydrofolate reductase rs1801131 variant among Saudi smokers.

Methylenetetrahydrofolate reductase (MTHFR) polymorphism plays a fundamental role in susceptibility to various diseases, including cancers and autoimmune diseases. In the current study, we aimed to compare genotype and allele frequency variations of rs1801131, one of the most common variants found in the MTHFR gene, among Saudi smokers and non-smokers. We hypothesized that genetic variations of this gene are responsible for many diseases, particularly those caused by cigarette smoking (CS) such as pulmonary diseases, oral cancer and lung cancer. We performed a case-control study on a sample of 235 healthy smokers and 239 healthy non-smokers in Saudi Arabia. The rs1801131 SNP genotypes were determined using a genotyping assay and multiple in silico algorithmic software programs were used to identify the effects and structural functions of the rs1801131 (Glu429Ala) mutation. Using chi-squared tests, we found that, among smokers, TG and GG genotype carriers had 0.209-fold (OR = 0.209, P < 0.005) and 0.427-fold (OR = 0.427, P = 0.003) lower risks of CS-related disease compared to TT reference genotypes. In addition, this protective effect was observed in Saudi smokers independent of age, gender, types of smoking, duration, and average daily smoking consumption. Filling a research gap by exploring this topic in the Saudi population, the current findings indicate that genotype and allele distributions of MTHFR rs1801131 polymorphism present fundamental protective effects against the risk of CS-related disease. These findings should be verified in future studies with larger sample sizes, different ethnicities, and patients suffering from CS-related diseases, such as oral cancer and lung cancer.

Association between methylenetetrahydrofolate reductase gene rs1801131 A/C polymorphism and urinary tumors' susceptibility.

BACKGROUND: The methylenetetrahydrofolate reductase (MTHFR) rs1801131 A/C variant results in a decrease in MTHFR enzymatic activity, which may play an important role in folate metabolism and is also an important source of DNA methylation and DNA synthesis. Several case-control studies have been conducted to assess the association of MTHFR rs1801131 polymorphism with the risk of urinary cancers, yet with conflicting conclusions. To derive a more precise estimation of above relationship, the association between the MTHFR rs1801131 A/C polymorphism and the risk of urinary cancer was performed. METHODS: A total of 28 case-control studies was identified. The odds ratios (OR) with 95% confidence intervals (CI) was calculated to assess. RESULTS: On one hand, we found that the MTHFR rs1801131 A/C polymorphism was associated with increased whole urinary cancers' risk (for example CA vs. AA: OR = 1.12. 95%CI = 1.01-1.24). On the other hand, we found that the MTHFR rs1801131 A/C polymorphism might increase bladder cancer risk both in Asian (C-allele vs. A-allele: OR = 1.35. 95%CI = 1.15-1.60) and African populations (CA vs. AA: OR = 1.63. 95%CI = 1.17-2.25). CONCLUSIONS: Our current analysis suggested that MTHFR rs1801131 A/C is associated with urinary cancers, especially bladder cancer.

Lack of association between MTHFR A1298C variant and Alzheimer's disease: evidence from a systematic review and cumulative meta-analysis.

OBJECTIVES: Previous studies have investigated the association between MTHFR A1298C (rs1801131) polymorphism and susceptibility to Alzheimer's disease (AD). Nevertheless, an ultimate conclusion remains obscure. We then executed this meta-analysis to estimate this association more precisely. METHODS: Related studies were systematically searched on PubMed, Embase, China National Knowledge Infrastructure, Google scholar, and AlzGene databases. The association was evaluated by reviewing the odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Publication bias, sensitivity analysis, and cumulative meta-analysis were performed to help draw a more definite conclusion. RESULTS: Ten eligible studies were finally enrolled in this meta-analysis. Lack of association between MTHFR A1298C polymorphism and AD risk was observed in five genetic models (allelic: OR = 1.17, 95% CI: 0.88-1.56; homozygous: OR = 1.15, 95% CI: 0.87-1.53; heterozygous: OR = 1.19, 95% CI: 0.76-1.86; dominant: OR = 1.23, 95% CI: 0.81-1.87; recessive: OR = 1.16, 95% CI: 0.89-1.52). The result of cumulative meta-analysis sorted by publication year was also detected a dynamic tendency of no correlation between MTHFR A1298C polymorphism and AD. CONCLUSION: This meta-analysis reveals that MTHFR A1298C polymorphism may not be associated with AD risk.