In the TGF-β1-induced colorectal cancer model, berberine significantly decreased the expression of miR-152 (targeting DNMT1), miR-429 (targeting DNMT3A), and miR-29a (targeting DNMT3A/3B), which suggested that berberine inactivates some tumor suppressor factors, including DNMT1 and DNMT3A/3B, through the regulation of the expression of the above miRNAs during colon cancer development. This evidence concerns the gene DNMT3A and colonic neoplasm.