Effects Of5-Aza-2’-deoxycytidine And Trichostatin A On Methylation And Expression Of RUNX3Gene In Vivo And Vitro

Objective: Gastric cancer is one of the most common malignant tumor in the world,and is the second large cancer died causes. In recent years, much research foundtumor-suppressor gene promoter area abnormal methylation is closely related to thedevelopment of cancer, RUNX3is one of the most important tumor suppressor genesrelated to gastric cancer, because tumor-suppressor genes methylation can be reversible,We use5-Aza-dC and TSA in gastric cancer cell lines SGC-7901and gastric cancernude rats, analyzes the effect of drug to tumor-suppressor genes RUNX3methylationlevel, mRNA expression level and protein expression level, for5-Aza-dC and TSA areused in the clinical treatment of gastric cancer providing the experiment foundation.Methods:(1)We cultured stomach cancer cell lines SGC-7901in vitro, take thelogarithm cell randomly divided into the normal control group,5-Aza-dC group, theTSA group and the5-Aza-dC+TSA group based on the design scheme to each drugintervention.(2)Raise BALB/c nu/nu nude rats, injection gastric cancer cells SGC-7901levitation liquid to it, randomly divided into the normal control group, the5-Aza-dCgroup, the TSA group and the5-Aza-dC+TSA group.(3) DNA, RNA and protein wereextracted from gastric cancer cell and the tumor of subcutaneous transplantation.(4) Themethylation level of RUNX3was detected by QMSP, mRNA and protein expressionlevel were detected by SqRT-PCR and Western-Blot, and the results were analysed.Results: RUNX3gene in the gastric cancer cells and cell planting tumor tissue were in high degree of methylation, but mRNA and protein expression level were low,5-Aza-dC and TSA can reduce gastric cancer cell lines SGC-7901and cell plantingtumor tissue RUNX3gene promoter’s methylation level and improve the mRNA andprotein expression level, the5-Aza-dC+TSA group’s effect was more apparent.Conclusion: RUNX3gene in the gastric cancer cell lines SGC-7901and cell plantingtumor tissue is in the high degree of methylation, and low mRNA and proteinexpression level,5-Aza-dC and TSA can reverse the RUNX3gene promotermethylation level, improve the mRNA and protein expression level. The two drugscombined can be more effective in reverse RUNX3gene promoter methylation levelandimprove the area mRNA and protein expression level.