ABSTRACT
Objective: Eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) is involved in the occurrence and development of various tumors. However, the effect of EIF4G2 in gastric cancer (GC) has not been fully explored. The purpose of this study was to explore the function and mechanism of EIF4G2 in GC. Methods: The Tumor Immune Estimation Resource 2.0 database was used to analyze EIF4G2 expression in various cancers and the relationship between EIF4G2 expression and tumor-infiltrating immune cells. Gene Expression Profiling Interactive Analysis was utilized to assess the EIF4G2 expression level and its effect on survival in GC. UALCAN was conducted to analyze EIF4G2 expression in various subgroups of GC. The Kaplan-Meier plotter was employed for survival analysis. Receiver operator characteristic (ROC) curve analysis was applied to evaluate the diagnostic role of EIF4G2 in GC. LinkedOmics was used to identify the co-expressed genes and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways. The Tumor-Immune System Interaction database was employed to analyze the correlation between EIF4G2 expression and tumor-infiltrating lymphocytes. The starBase web platform was used to predict the upstream microRNAs and long noncoding RNAs. Results: EIF4G2 expression was upregulated in GC tissues compared to normal controls. High expression of EIF4G2 indicated poor prognosis in GC. ROC analysis revealed that EIF4G2 had good diagnostic ability to distinguish GC from normal tissues. Immune infiltration analysis indicated that EIF4G2 expression may be involved in the modulation of tumor immune infiltration in GC. Finally, we determined that the Taurine Upregulated 1 (TUG1)/hsa-miR-26a-5p/EIF4G2 axis was the most likely regulatory pathway involved in GC development. Conclusions: EIF4G2 was upregulated in GC and elevated expression of EIF4G2 indicated unfavorable prognosis. Moreover, EIF4G2 expression may be involved in the regulation of tumor immune cell infiltration. The TUG1/hsa-miR-26a-5p axis is a likely upstream regulatory mechanism of EIF4G2 in GC. EIF4G2 may thus serve as a prognosis biomarker and present a new therapeutic target.
ABSTRACT
Rationale: Immune dysfunction is thought to play an important role in the pathogenesis of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD). However, the underlying mechanism requires further investigation. Vasoactive intestinal peptide (VIP) has immune regulatory functions, but its role in immune regulatory activities in the intestinal mucosa is not fully understood. This study aims to elucidate the role of VIP in the regulation of regulatory B cell (Breg) function in the intestine. Methods: Peripheral blood samples were collected from UC patients and healthy control (HC) subjects. Bregs were isolated from these samples and their immune regulatory function was analyzed. A murine colitis model was established to test the role of VIP in inhibiting inflammation in the intestine. Results: Serum IL-10 and VIP levels were lower in IgE+ (≥0.35 IU/mL) UC patients than that in HC subjects. The immune suppressive function of Bregs isolated from IgE+ UC patients was impaired. IL-10 mRNA decayed spontaneously in Bregs, which was reversed by VIP added to the culture. Tristetraprolin (TTP) bound IL-10 mRNA to speed its decay, which was blocked by VIP in the culture. Administration of VIP efficiently inhibited experimental colitis. Conclusions: Insufficient VIP levels in the microenvironment speeds IL-10 mRNA decay to cause Breg dysfunction. Administration of VIP can inhibit experimental colitis, suggesting the translational potential of VIP in the treatment of IgE+ UC.
