The influence of folate supplementation on global gene expression in normal colonic mucosa of subjects with colorectal adenoma.

Scope: We determined whether short-term supplementation with a physiological dose of folate alters global gene expression in the normal colonic mucosa of subjects with colorectal adenoma.

Methods And Results: Fourteen subjects with adenoma, randomised to receive folic acid (400μg/day, n = 6) or placebo (n = 8) for 10 weeks, had blood samples and colonic tissue biopsies collected before and after the intervention. RNA extracted from colonic tissue samples was used to determine global gene expression in the colon using Affymetrix® Microarray GeneChips and real-time RT-PCR.

Short-term folate supplementation in physiological doses has no effect on ESR1 and MLH1 methylation in colonic mucosa of individuals with adenoma.

Background/aims: Low folate intake may increase risk of colorectal cancer by altering gene-specific methylation in the colon. We determined whether supplementation with physiological doses of folate could alter methylation in the oestrogen receptor 1 (ESR1) and mutL homolog 1 (MLH1) genes in colonic mucosa of subjects with colorectal adenoma.

Methods: This was a randomised, double-blind, placebo-controlled trial.