RNF220 promotes gastric cancer growth and stemness via modulating the USP22/wnt/β-catenin pathway

Gastric cancer (GC) is a prevalent malignancy that seriously threatens the health and life of patients. Although Ring finger 220 (RNF220) has been demonstrated to participate in the development of various cancers, its role and mechanism in GC remain undiscovered. The expression of RNF220 was determined by The Cancer Genome Atlas (TCGA) database and Western blot. Additionally, the overall survival (OS) and post-progression survival (PPS) were analyzed based on the levels of RNF220 in the TCGA database. The role and mechanism of RNF220 in growth and stemness were investigated using cell counting kit-8, colony formation, sphere-formation, co-immunoprecipitation, and Western blot experiments. Furthermore, the role of RNF220 was investigated in a xenografted mouse model. The expression of RNF220 was found to be upregulated in GC, which predicted unfavorable OS and PPS in patients with GC. Knockdown of RNF220 reduced cell viability, colony numbers, numbers of spheres formation, and the relative protein levels of Nanog, Sox2, and Oct4 in both AGS and MKN-45 cells. Moreover, overexpression of RNF220 increased cell viability and the numbers of spheres formation in MKN-45 cells. Mechanistically, RNF220 bound to USP22, and interference of RNF220 downregulated the Wnt/β-catenin axis via USP22, which was confirmed by the overexpression of USP22 in both cell lines. Furthermore, silencing of RNF220 significantly decreased tumor volume and weight, the level of Ki-67, and the relative protein levels of USP22, β-catenin, c-myc, Nanog, Sox2, and Oct4. Taken together, downregulation of RNF220 suppressed GC cell growth and stemness by downregulating the USP22/Wnt/β-catenin axis.