Promoter Methylation To Loss Of OPCML Expression In Progression Of Gastric Cancer

Objective： To discuss the loss of OPCML expression in gastric cancercells, and its association with methylation of promoter CpG islands, andto analyze the proliferation of ectopic expression of OPCML in gastriccancer cells.Methods： OPCML expression was detected in human gastric cancer celllines by RT-PCR. we analyzed OPCML gene methylation using MSP. OPCMLexpression in response to demethylation was detected by RT-PCR. The cellviability assay was performed by mononuclear cell direc cytotoxicityassay(MTT). Cell colony formation was detected by actopic expression ofOPCML in tumor cell lines. Western blot were used to detect theexpression of OPCML protein in gastric cancer cell lines MKN45.Results：(1) OPCML expression in gastric cancer cells is aberrantlyreduced, in contrast to nomal gastric tissue.(2)The OPCML gene was morecommonly methylated in gastric cancer cells such as AGS and MKN45thannormal gastric tissue.(3)Demethylation by5-AZA, OPCML expression isup-regulated.(4)Ectopic expression of OPCML in gastric cancer cells withendogenous silencing led to strong inhibition of cell viability.(5)Ectopic expression of OPCML in gastric cancer cells with endogenoussilencing led to strong inhibition of cell colony formation.(6)Western bolt demonstrated that OPCML protein was not expressed in gastric celllines.Conclusion：(1) The OPCML gene might be tumor suppressor genes. OPCMLexpression is down-regulated in gastric cancer cells.(2) It is associatedwith methylation of promoter CpG island.(3) Demethylation by5-AZArestored OPCML expression in gastric cancer cells.(4)Ectopic expressionof OPCML in gastric cancer cells with endogenous silencing led to stronginhibition of cell viability.(5) Ectopic expression of OPCML in gastriccancer cells with endogenous silencing led to strong inhibition of cellcolony formation.