Construction of an miRNA-mRNA regulatory network in colorectal cancer with bioinformatics methods

Colorectal cancer (CRC) is the third most common cancer worldwide. This study aimed to explore the regulatory mechanisms of miRNAs in CRC. Differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) in CRC tissue samples compared with control samples in mRNA and miRNA datasets were screened. Functional and pathway enrichment analysis of the DEGs was carried out. Targets of the DEMs were identified. Overlaps between the DEGs and targets of DEMs were selected. The miRNA-mRNA regulatory network of these overlaps was constructed and visualized. The candidate genes selected were validated by quantitative real-time PCR. DEGs were identified and considered DEGs-1 and DEGs-2. A total of 584 genes in DEGs-1 and 527 genes in DEGs-2 were obtained, including 465 overlaps, and 44 DEMs were identified. The overlaps were enriched in 46 Gene Ontology terms and 19 Kyoto Encyclopedia of Genes and Genomes pathways. Moreover, 137 overlapped genes between targets of the DEMs and the 465 overlaps were obtained. The miRNA-mRNA regulating network of the 137 overlapped genes was constructed. Extracellular matrix-related proteins and pathways might play critical roles in the development of CRC. The quantitative real-time PCR results of the candidates were in agreement with the bioinformatics analysis. miR-128, miR-182, and miR-143 might be key miRNAs regulating cell proliferation and metastasis of CRC.