Research on the expression and regulation of ASPP2 and its methylationin human gastric carcinoma cell / 中华内分泌外科杂志

ABSTRACT

Objective To investigate the relationship between the expression of ASPP2 mRNA and the methylation of ASPP2 gene in gastric cancer cells,to observe the inhibitory effect of 5-Aza-CdR on the growth of gastric cancer cells,to observe the effect of demethylation on the expression of ASPP2 mRNA and the methylation of ASPP2 gene in gastric cancer cells,and to explore the molecular mechanism of gastric cancer.Methods Real-time PCR was used to detect the expression of ASPP2 mRNA in two gastric cancer cells and normal gastric epithelial cells.BSP was used to detect the methylation of ASPP2 gene in two gastric cancer cells and normal gastric epithelial cells.CCK-8 was used to detect the growth inhibition rate of gastric cancer cells treated with 5-Aza-CdR of different concentrations,then they were used to detect expression of ASPP2 mRNA and the methylation of ASPP2 gene in gastric cancer cells again after the demethylation.Results ① The expression of ASPP2 mRNA in MKN-45 cells was significantly lower than that in GES-1 cells(P＜0.01).The expression of ASPP2 mRNA in MGC-803 cells was significantly lower than that in GES-1 cells (P＜0.01).There was no significant difference in MGC-803 cells and MKN-45 cells(P＞0.05).② The methylation rate of ASPP2 in MKN-45 cells was significantly higher than that in GES-1 cells (P＜0.01).The methylation rate of ASPP2 in MGC-803 cells was not significantly different from that in GES-1 cells (P＞0.05).The methylation rate of ASPP2 in MKN-45 cells was significantly higher than that in MGC-803 cells (P＜0.01).③ At the same time,the growth inhibition rate of each 5-Aza-CdR concentration group increased as the drug concentration depended.4.The expression of ASPP2 mRNA in MKN-45 cells was significantly higher than that before treatment (P＜0.01),the expression of ASPP2 mRNA in MGC-803 cells was not significantly different from that before treatment(P＞0.05).The methylation rate of ASPP2 in MKN-45 cells was significantly lower than that before treatment (P＜0.01).The methylation rate of ASPP2 in MGC-803 cells was not significantly different from that before treatment (P＞0.05).Conclusion ① Abnormal hypermethylation of ASPP2 gene in MKN-45 cells may be a molecular mechanism of decreased ASPP2 mRNA expression.② 5-Aza-CdR can inhibit the growth of MKN-45 and MGC-803 cells,and it can enhance the expression of ASPP2 mRNA in MKN-45 cells.Reversal of methylation in the promoter region of ASPP2 gene is the possible mechanism.③ Abnormal hypermethylation of the promoter region of ASPP2 gene may lead to silencing of mRNA expression that may be associated with gastric cancer.