Abstract: Objective To study the effect of 5-Aza-2-deoxycytidine (AZA) on re-expression of the hypermethylated and silenced CHD5(Chromodomain, helicase, DNA-binding 5) gene in human colon carcinoma cell and cell proliferation. Methods Lovo and SW480 cells were exposed to 5μmol/L AZA for 72h, and then CHD5 expression was determined by quantitative RT-PCR (qPCR), methylation status of CHD5 genes was determined by bisulfite sequencing PCR (BSP), and the proliferation of the cells was evaluated by MTT assay. Results After treatment with 5μmol/L AZA, the promoter region of the CHD5 gene exhibited a demethylation status, and CHD5 mRNA was re-expressed．Meanwhile, the growth of Lovo and SW480 cells were reduced. Conclusions AZA could reverse methylation of CHD5 gene to regulate the expression of CHD5 gene, and could effectively inhibit the cellular proliferation of human colon carcinoma cell.

Key words: CHD5 gene, methylation, Colon Carcinoma