OBJECTIVE To study the mechanism of Qingre huashi decoction in the treatment of gastric cancer by intervening in miRNA-155 and inhibiting Wnt/β-catenin signaling pathway. METHODS Thirty nude mice were randomly divided into model group， control group （0.004 g/kg cisplatin+0.02 g/kg fluorouracil）， overexpression group， Qingre huashi prescription low-dose， medium-dose and high-dose groups （2.71， 5.43， 10.86 g/kg）， with 5 mice in each group. The overexpression group was inoculated with miRNA-155 AGS cell line， and the other groups were inoculated with AGS cells to induce tumor-bearing gastric cancer model. The control group was given relevant medicine intraperitoneally， and other groups were given relevant medicine or normal saline intragastrically， once a day， for 3 consecutive weeks. The weight of tumor tissue in nude mice was determined； the pathological morphology of tumor tissue was observed； the miRNA-155 expression， mRNA and protein expressions of Wnt7， β-catenin and T- cell factor-4（TCF-4） in tumor tissue were detected. RESULTS Compared with the model group， the tumor weights of nude mice in the control group， the overexpression group and Qingre huashi decoction high-dose group were significantly reduced （P＜0.05）； mRNA and protein expressions of Wnt7， β -catenin and TCF-4 were significantly decreased （P＜0.05）， while miRNA-155 expression was increased significantly （P＜0.05）. Tumor cells exhibited varying degrees of loose arrangement， shallow nuclear staining， and necrotic foci. CONCLUSIONS Qingre huashi decoction can inhibit the protein and mRNA expressions of Wnt7， β-catenin and TCF-4 in Wnt/β-catenin signaling pathway by up-regulating miRNA-155， thus inhibiting the tumor growth of tumor-bearing nude mice.

Objective To investigate Helicobacter pylori combined with N-methyl-N-nitrosourea (MNU) gavage for preparing balb/c mouse gastric cancer model.Methods Eighty balb/c mice were randomly divided into four groups after 1-week adaptive feed,normal group,model group Ⅰ,Ⅱ and Ⅲ,20 cases in each group.The model group Ⅰ,Ⅱ and Ⅲ were given Helicobacter pylori bacteria liquid (CFU=109/mL) gavage,once every other day for 5 times;then,the freshly configured MNU solution 0.15,0.3,0.6 mL gavages were in turn given,MNU and pure water allocation ratio was 5mg:3mL.Once gavage per week for continuous 10 weeks.Results The model group II had 66.67% adenocarcinoma,the model group I were gastritis with mild atypical hyperplasia,and all mice in the model group III died.Conclusion This method can prepare the gastric cancer model.