Abstract: Objective To explore the expression and significance of the Crk SH3-domain-binding guanine-nucleotide exchange factor(C3G) in the gastric cancer tissue.
Methods Using Oncomine to analyze the differences in expression of C3G in tumor tissues and para-carinoma tissues.Collecting 121 postoperation gastric cancer patients' clinical data who is up to standard,from December 2012 to December 2015.And detecting the expression of C3G protein in their cancerous tissues and para-carinoma tissues by immunohistochemistry.Then analyzing the relationship between C3G protein expression and clinicopathological characteristics and prognosis in these patients.
Results Bioinformatics analysis results showed C3G was high expression in gastric cancer tissue than normal tissue(P<0.05),and in immunohischemistry,the positive expression rate in cancerous tissues and para-carinoma tissues was 70% and 31%.Through Kaplan-Meier survival curve analysis,the survival rate of the patients,who the C3G expression whether positive,was significative(χ2=4.384,P<0.05).And the expression of C3G was related to the T stage of the tumor and lymph nodes metastasis(P<0.05),but was not to the age,sex and differentiated degree of tumor(P>0.05).
Conclusion C3G is highly expressed in gastric cancer tissues,and its high expression is related to the development of gastric cancer and its poor prognosis.

Key words: gastric cancer, Crk SH3-domain-binding guanine-nucleotide, expression； prognosis