Three novel microRNAs based on microRNA signatures for gastric mucosa-associated lymphoid tissue lymphoma

This study aimed to identify novel microRNAs (miRNAs) that play crucial regulatory roles in the pathogenesis of mucosa-associated lymphoid tissue (MALT) lymphoma by retrieving and analyzing the miRNA expression profile GSE23877. Differentially expressed miRNAs between gastric MALT lymphoma samples and human tonsil tissue samples as well as their target genes were identified. The transcriptional regulatory relationships between miRNAs and target genes were analyzed, and the regulatory network between them was constructed. Target genes annotated as transcription factors (TFs) were screened, and an miRNA-target gene regulatory network was established. Moreover, the expression levels of miRNAs and target genes as well as the correlation between them were verified. In total, 53 upregulated and 25 downregulated miRNAs were obtained, for which 35 and 25 experimentally validated miRNA-target interactions, respectively, were screened. Some miRNAs were significantly enriched in certain pathways; for example, miR-320a was enriched in systemic lupus erythematosus and ribosome, miR-622 in the p53 signaling pathway and chronic myeloid leukemia, and miR-429 in cancer-related pathways. In addition, upregulated miRNAs, including miR-320a, miR-940, and miR-622, and downregulated miRNAs, including miR-331-3p and miR-429, were hub nodes in the miRNA-target gene regulatory network, and the TF MYC was a co-target of miR-320a, miR-622, and miR-429. The expression trends of miR-320a and miR-429 as well as of some of their target genes were consistent with those in the results of microarray analysis. In conclusion, miR-320a, miR-622, and miR-429 are possibly novel miRNAs participating in the pathomechanism of gastric MALT lymphoma.