Genistein inhibits invasion and migration of colon cancer cells by recovering WIF1 expression

Colon cancer is characterized by invasion and migration. DNA methylation of CpG islands in tumor suppressor genes is considered to be an epigenetic mechanism underlying cancer development. Epigenetic silencing of a gene may be reversed by drugs, including genistein. The present study aimed to determine the effect of genistein on Wnt inhibitory factor 1 (WIF1) and invasion, and migration of colon cancer cells. The viability of HT29 colon cancer cells was suppressed by genistein in a dose dependent manner. Following 72 h of treatment with 10, 20 and 60 mu mol/l genistein, increased demethylation of WIF1 was induced in a dose-dependent manner. Additionally, the invasive/migratory abilities of cells treated with genistein decreased in a dose-dependent manner. Reverse transcription-quantitative polymerase chain reaction and western blot analyses were performed to identify the mRNA and protein expression levels of invasion/migration-associated factors. Following treatment with genistein, matrix metalloproteinase (MMP) 2 and MMP9 expression levels decreased, whereas the expression of metalloproteinase inhibitor 1 and E-cadherin increased significantly. In addition, the expression levels of proto-oncogene Wnt-1 (Wnt-1)/-catenin pathway-associated factors, -catenin, c-Myc proto-oncogene protein and cyclin D1 decreased in a dose-dependent manner following treatment with genistein. The invasive/migratory abilities of cells transfected with WIF1-small interfering (si) RNA, and those transfected with WIF1-siRNA and treated with genistein, increased notably compared with the control group. The present study demonstrated that genistein was able to inhibit the cell invasion and migration of colon cancer cells by inducing demethylation, and recovering the activity of WIF1 by altering the expression of invasion-associated factors, and components of the Wnt signaling pathway.