Summary: | 碩士 === 中山醫學大學 === 營養學系碩士班 === 101 === Folate plays an important role in the progression of colorectal cancer (CRC). 5,10-methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in one carbon metabolism, which converts the 5,10-methylenetetrahydrofolate to the 5-methyltetrahydrofolate and the reaction provides a methyl group for homocysteine to convert methionine. Previous studies reported that MTHFR 677C→T gene polymorphism which there was mutation in T allele had a decreased risk of CRC. However, the results of the association of MTHFR 677C→T gene polymorphism with colorectal cancer were quite inconsistent. Therefore, the purpose of this study was to investigate the association of serum folate, MTHFR 677C→T gene polymorphism and plasma homocysteine with the risk of CRC. This study was a case-control study. Patients with CRC and healthy subjects were recruited from Taichung Veterans General Hospital and were assigned to either the case group (n = 168) or the control group (n = 188). Fasting blood samples were drawn to measure serum folate, MTHFR 677C→T genotypes and plasma homocysteine. Results showed serum folate and homocysteine concentrations of the case group with CC genotype were higher than the control group with CC genotype. Plasma homocysteine in the case group with T-allele mutation (CT genotype + TT genotype) were higher than the control group with T-allele mutation. Whether or not adjusting the confounding factors, there was no significant association of MTHFR 677C→T genotypes with serum folate and plasma homocysteine concentration. However, serum folate was strongly inversely associated with plasma homocysteine (β= -0.07, p<0.001). Serum folate (OR, 1.07; 95 % CI, 1.03-1.10) and plasma homocysteine concentration (OR, 1.32; 95 % CI, 1.20-1.45) significantly increased the risk of CRC. Nevertheless, MTHFR 677C→T genotypes had no effect on the risk of CRC. High plasma homocysteine concentration might be a risk factor for CRC, while the association between serum folate and CRC need further study.
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