Evaluation of RNF11 as a diagnostic biomarker for gastric cancer through comprehensive TCGA and GEO data mining

Background: Gastric cancer (GC) is a malignant disease that affects the life and health of people all over the world. It is particularly important to explore molecular markers for molecular diagnosis and targeted therapy of gastric cancer. This paper aims to explore the important role of RNF11 in the occurrence and development of gastric cancer and its effectiveness as a new target by combining TCGA and GEO database. Methods: We first collected data from the Cancer Genome Atlas (TCGA) and Integrated Gene Expression (GEO) databases to analyze the relationship between the expression level of RNF11 in tissues and the clinicopathological characteristics of patients. COX regression analysis was used to verify the prognostic risk factors of gastric cancer. Then, the differentially expressed genes (DEGs) data were obtained from the GEO dataset, the heat map of differentially expressed genes was drawn, and the protein interaction network was constructed. TCGA data were used as the validation set, and gene set enrichment analysis (GSEA) was used to analyze the DEG data to identify the enriched functions and pathways related to RNF11 and their relationship with immune infiltration. Finally, we used RT-PCR, IHC, WB, immunofluorescence and other basic experimental techniques to verify the expression of RNF11 in gastric cancer. Results: The expression level of RNF11 mRNA in gastric cancer tissues is correlated with T stage, N stage and Grade grade of patients. Univariate and multivariate COX regression analysis showed that age, T stage, N stage and distant metastasis were risk factors affecting the prognosis of patients (p=0.049). RNF11 could be used as an independent prognostic factor for gastric cancer. The differential expression of RNF11 can affect a variety of differentially expressed genes, and CHMP3, FAM73A, RNF31, and SLC35E1 are the direct interacting proteins of RNF11. Gene set enrichment analysis (GSEA) showed that RNF11-related DEGs were mainly enriched in signaling pathways related to the occurrence and development of gastric cancer, and RNF11 was associated with a variety of immune cell infiltration. By RT-PCR, IHC, WB and immunofluorescence verification, we found that the expression level of RNF11 was significantly increased in gastric cancer. Conclusions : RNF11 may play an important role in the occurrence and development of GC expected to serve as a molecular marker for molecular diagnosis and targeted therapy of GC.