Identification of a miRNA-mRNA network associated with lymph node metastasis in colorectal cancer

Lymph node metastasis is an important step in the progression of colorectal cancer (CRC); however, the underlying mechanisms are still unknown. The aim of the present study was to identify the gene expression pattern during lymph node metastasis in CRC and to identify upstream microRNAs (miRNAs) to explore the underlying mechanisms in detail. A total of 305 differently expressed genes (DEGs) were identified, including 227 upregulated genes and 78 downregulated genes in lymph node metastasis. Pathway and process enrichment analysis demonstrated that DEGs were significantly enriched in 'NABA CORE MATRISOME', 'extracellular matrix assembly', 'antimicrobial humoral response' and 'Toll-like receptor signaling' pathways. The top 10 hub genes were identified by protein-protein interaction network, and sub-networks revealed that these genes were involved in significant pathways, including 'neutrophil chemotaxis' and 'Smooth Muscle Contraction'. In addition, 73 mature differently expressed miRNAs associated with lymph node metastasis were identified, of which 48 were upregulated and 25 were downregulated. Six miRNAs were identified to regulate DEGs. Additionally, based on the relationship between miRNAs and transcription factors, a miRNA-TF-mRNA network was constructed. In conclusion, DEGs, miRNAs and their interactions and pathways were identified in lymph node metastasis in CRC, which provided insight into the mechanism of CRC metastasis and may be used to develop novel targets for CRC treatment.