Effects Of 5-Aza-CdR On The Expression Of BGC-823 Methyltransferase And Its Inhibitory Effect On Proliferation

BackgroundIn recent years, gastric cancer is one of the highest incidence of malignant tumorsin our country, and the trend of younger onset age.The occurrence of gastric cancer isassociated with methylation of some tumor suppressor genes. The methylation of genepromoter region in vivo led to the expression of tumor suppressor gene silencing, sothat the cell canceration.DNA methyltransferase (Dnmts) can promote certain genemethylation, especially some tumor suppressor genes, resμ lting cells in normal tissueto cancer cell differentiation.In addition,5-Aza-2’-deoxycytidine, which is DNAmethyltransferase inhibitors, can reduce level of DNA methylation in cells, to achievethe purpose of demethylation. Therefore, the study of DNA methylation will provide anew train of thought for the pathogenesis of gastric cancer from molecμ lar level.Besides, it can make us understanding of the biological characteristics of gastriccancer cells more clear that studying the restrain condition of5-Aza-2’-deoxycytidineon gastric cancer cell lines, as well as providing the molecμ lar basis for the clinicalmedication.5-FU is a commonly used treatment of gastric cancer chemotherapydrugs, clinical studies that5-FU and5-Aza-2’-deoxycytidine combination on gastriccancer cell growth inhibition, also provide certain theoretical support for clinicaltreatment.Objective1、The levels of DNA methyltransferase expresse in the gastric cancer cell line BGC-823;2、 Exploring the different concentration of5-Aza-2’-deoxycytidine impact on thelevels of DNA methyltransferase expression between Dnmts and p16genes;3、5-FU together with5-Aza-2’-deoxycytidine effect on gastric cancer cell linesBGC-823growth inhibition.Methods:1、BGC-823gastric cancer cell line proliferation subcμlture;2、Determined different concentrations of5-Aza-CdR effect on gastric cancer celllines growth inhibition by MTT method.3、Determined different concentrations of5-FU effect on gastric cancer cell linesgrowth inhibition by MTT method.4、Detection of different concentration of5-Aza-CdR effect on the mRNA levelexpression of Dnmts and P16genes in gastric cancer cells BGC-823by Real-time PCR.5、 Using the medical statistical software SPSS17.0analysis datas.Results:1、BGC-823gastric cancer cells by different concentration of5-Aza-the CdR and5-FU, compared with the control group, cell growth speed slow down in differentdegrees and the inhibition of cell growth significantly.Among them,5-Aza-CdR halfinhibitory concentration is0.49μmol/L on gastric cancer cell,5-FU half inhibitoryconcentration is8.78μmol/L.2、The resμlt of Real-time PCRintegrated that mRNA expression of Dnmts gene ingastric cancer cell line BGC–823have been cut down by5-Aza-CdR todemethylation process, and up-regμlation expression of P16gene.Joint with5-FUafter processing, the mRNA expression of Dnmts gene also has been cut down.Conclusions:1、DNA methyltransferase in gastric cancer cells BGC-823has been highexpression.2、5-Aza-CdR inhibiting cell proliferation reaction by down-regμlation mRNAexpression of Dnmts gene in gastric cancer cell line BGC-823, and5-FU hassynergistic inhibition effect to its proliferation.3、5-Aza-CdR has a role in demethylation on gastric cancer cell line BGC–823by down-regμlation expression of Dnmts gene, so that the expression of P16genewas able to rise.