Objective To determine whether aberrant methylation is a contribution factor to transcriptional inactivation of DLC-1 in colon cell lines.Via the investigation of the expression and methylation status of DLC-1(deleted in liver cancer,DLC-1)gene in human colon cell lineswere investigated.Methods Reverse transcipatase PCR was used to explore mRNA expression of the DLC-1 gene.Methylation specific polymerase chain reaction(MSP)and sodium bisulfite genomic sequencing(BSP)were used to test promoter methylation of DLC-1 gene in CaCo-2,LoVo and HT-29.The hypermethylation status was reversed by adding various concentration(0,5,10 μmol·L-1)of 5-aza-2’-deoxycytidine(5-Aza-CdR),a demethylating agent.Results DLC-1 gene was obviously expressed in CaCo-2 and LoVo cell lines,both cell lines showed no methylation.On the contrary,loss of DLC-1 mRNA expression was detected in HT-29 due to the methylation of CpG island of DLC-1 gene.After the treatment of 5-Aza-CdR in hypermethylation cell line HT-29,the expression of DLC-1 mRNA was increased obviously.Conclusion This promoter hypermethylation is correlated with DLC-1 gene expression in human colon cancer HT-29 cell line and plays a key role in DLC-1 silencing. |