Integrative analysis of immune microenvironment-related CeRNA regulatory axis in gastric cancer.

This study aimed to identify significant immune microenvironment-related competing endogenous RNA (CeRNA) regulatory axis in gastric cancer (GC). Analysis of differentially expressed mRNAs (DEmRNAs), miRNAs (DEmiRNAs), and lncRNAs (DElncRNAs) was performed for the microarray datasets. After abundance analysis of immune cell's infiltration, immune-related mRNAs and lncRNAs were obtained. Meanwhile, according to the Pearson correlation coefficient between immune-related mRNAs and lncRNAs, the co-expression mRNA-lncRNA pairs were screened. Furthermore, the target genes of co-existance miRNAs were predicted, and miRNA-lncRNA pairs were identified. Finally, the lncRNA-miRNA and miRNA-mRNA relationship regulated by the same miRNA was screened. Combining with the co-expression relationship between lncRNA and mRNA, the CeRNA network was constructed. In abundance analysis of immune cell's infiltration, a total of eight immune cells were obtained, in addition, 83 immune-related DElncRNAs and 705 immune-related DEmRNAs were screened. KEGG pathway enrichment analysis showed that these mRNAs were mainly involved in PI3K-Akt signaling pathway and human papillomavirus infection, while lncRNA were relevant to gastric acid secretion. A total of 25 miRNAs were significantly associated with immune-related mRNAs, such as hsa-miR-148a-3p, hsa-miR-17-5p, and hsa-miR-25-3p. From the mRNA-miRNA-lncRNA CeRNA network, we observed that AC104389.28─miR-17-5─SMAD5 axis and LINC01133─miR-17-5p─PBLD axis played a crucial role in the development of GC. Furthermore, resting memory CD4 T cells and plasma cells were closely associated with the pathogenesis of GC, and these immune cells might be affected by the key genes. The present study identified key genes that associated with immune microenvironment in GC, providing potential molecular targets for immunotherapy of GC.