TRIM11 Promotes Gastric Cancer Tumorigenesis And Progression By Activating The Wnt/β-catenin Signaling Pathway

Background:Gastric cancer is one of the most common gastrointestinal malignancies in China and secondly ranks in leading causes of cancer-related death.Despite advances in diagnostic techniques,surgical treatment,chemotherapy,and immunotherapy for gastric cancer,the overall 5-year survival rate for patients with gastric cancer remains stagnant.The tumorigenesis and progression of gastric cancer is a complex sequential process involving multiple steps,multiple genes and multiple pathways.Therefore,it is of great significance to further explore the abnormally expressed molecules and their regulatory mechanisms during the tumorigenesis and progression of gastric cancer.The up-regulated expression of E3 ubiquitin ligase TRIM11 and the abnormal activation of Wnt/β-catenin signaling pathway play an important role in the occurrence and metastasis of tumors.However,the role of TRIM11 in gastric cancer,and the correlation between TRIM11 and Wnt/β-catenin signaling pathway have not been reported and need to be further studied.This study aims to investigate the biological roles of TRIM11 in gastric cancer and the mechanism by which TRIM11regulates the Wnt/β-catenin signaling pathway.Methods:The TCGA database,IHC and western blotting were utilized to investigate the expression of TRIM11 in gastric cancer tissues.And the relationship between TRIM11 and the clinicopathological characteristics and survival prognosis of patients was analyzed byχ~2 test.Interfering RNA and overexpressed plasmids were designed to establish cell models for TRIM11 knockdown and overexpression.The CCK-8,colony formation,wound Healing and transwell assays were performed to detect the role of TRIM11 in cell proliferation,migration and invasion.Quantitative real-time PCR(q RT-PCR),co-immunoprecipitation(co-IP)and CHX experiments were used to confirm the mechanism by which TRIM11 activates the Wnt/β-catenin signaling pathway.After co-transfection of TRIM11 si RNA and Axin1 si RNA in gastric cancer cells,western blotting and RT-PCR assays were used to detect the expression of TRIM11,Axin1 and Wnt/β-catenin pathway downstream targets to determine whether TRIM11 is dependent on Axin1 to regulate Wnt signaling pathway activity.And cell functional experiments were used to verify whether AXIN1 knockdown could partially reverse the effects of TRIM11 on the cell proliferation and invasion of gastric cancer cells.Subcutaneous xenograft tumor model was established in nude mice to verify the role of TRIM11 in gastric cancer tumorigenesis and progression.Results:TRIM11 was highly expressed in gastric cancer tissues,and its overexpression was significantly correlated with pathological type,TNM stage and prognosis of gastric cancer patients(P<0.05).TRIM11 deletion suppressed the cell proliferation,colony formation,migration and invasion abilities of GC cells.On the contrary,overexpression of TRIM11 had the opposite effect.Mechanistically analysis showed that TRIM11 knockdown decreased the expression ofβ-catenin and Wnt pathway downstream genes(such as cyclin D1 and c-Myc)through inhibiting AXIN1expression.Further analysis showed that TRIM11 could bind and shorten the half-life period of AXIN1.Moreover,correlation analysis showed that the protein expression of TRIM11 and Axin1 was negatively correlated in gastric cancer tissues.Our study also found that knockdown of Axin1 could partially reverse the effects of down-regulation of TRIM11 on the proliferation and invasion of gastric cancer cells through modulation of the Wnt/β-catenin pathway.In addition,in vivo experiments further confirmed that TRIM11 depletion could significantly inhibit tumor growth by inhibiting the activity of Wnt signaling pathway,which further supported the results of cytological experiments.Conclusion:E3 ubiquitin ligase TRIM11 promotes gastric cancer tumorigenesis and progression by activating the Wnt/β-catenin pathway via suppressing the expression of AXIN1 protein.