The effect of folic acid on DNA methylation of tumor-related genes in healthy human peripheral blood mononuclear cells / 中华消化杂志

ABSTRACT

Objective To investigate the effect of folic acid on the DNA methylation of tumorrelated genes promoters in healthy human peripheral blood mononuclear cells(PBMC). Methods Ten healthy volunteers were divided into two groups, and were randomized to receive either 5 mg folic acid (n=5)or placebo(n = 5) , one time per day for 3 months. The serum folic acid concentration was detected with chemiluminescence enzyme immunoassay kit before and after the intervention. The methylation statuses of five tumor-related genes promoter, including oncogenes c-myc, c-Ha-ras,tumor suppressor genes p16INK4A, E-cadherin and mismatch repair gene hMLH1 in PBMC were detected by bisufite sequencing. Results After folic acid intervention, the level of serum folic acid increased significantly in intervention group (t= -4. 739,P<0. 05) , however no significant difference in control group. After three-month folic acid intervention, the level of methylation of oncogene c-myc promoter increased from 4%, 3. 3%, 4. 1% before intervention, one week after intervention, one month after intervention respectively to 8%(t= -4. 079,P<0. 05), while no significant change in placebo taken group. Before and after the folic acid intervention, there was no significant difference of DNA methylation of other tumor-related genes promoter, including c-Ha-ras、E-cadherin、p16INK4Aand hMLH1. Conclusion Folic acid intervention can up-regulate DNA methylation of oncogene c-myc promoter, but can not affect the promoter methylation status of tumor suppressor genes E-cadherin,p16INK4Aand hMLH1.