Effects of S-ademetionine on proliferation of gastric cancer cell lines and methylation of c-myc and uPA genes / 中华消化杂志

ABSTRACT

Objective To investigate the impacts of S-ademetionine (SAM) on cell cycles,apoptosis and invasive capacity of gastric cancer cell lines,and its effects on methylation and expressions of c-myc and uPA.Methods MKN-28,SGC-7901 and MKN-45 cells were treated with gradient concentrations of SAM(0,2 and 4 mmol/L) for 72 hours.The changes of cell cycles and apoptosis were detected by flow eytometry,and invasion was detected by transwell assay.The expressions and methylations of c-myc and uPA were examined by RT-PCR and MSP,respectively.Results The cell apoptosis significantly increased and cell invasive capacity was restrained in three cell lines with increase of SAM concentration (all P values<0.01).In SGC-7901,the cell percentage of G0/G1 phase significantly increased [(74.53±2.49)% vs.(56.67±1.18)%,P<0.053,whereas the cell proliferation index (PI) decreased [(25.50±2.46)% vs.(43.33±1.18)%,P<0.05] in comparison with controls.The expressions of c-myc and uPA mRNA in SGC-7901,uPA mRNA in MKN-45 and in 4 mmol/L SAM treated MKN-28 significantly decreased.The methylations of c-myc gene in SGC-7901 and uPA gene in three cell lines were reversed after treated with SAM.Conclusions SAM reduces expressions of c-myc and uPA by reversing the methylations of c-myc in SGC-7901 and uPA in all three cell lines.However SAM,as methyl donor,can restrain the development and progression of tumor when hypomethylation widely presents in cancer.