Revealing the molecular mechanism of colorectal cancer by establishing LGALS3-related protein-protein interaction network and identifying signaling pathways.

LGALS3 plays a role in colorectal cancer, however, the detailed molecular mechanism remains to be determined, while signaling pathways provide valuable information for understanding the underlying mechanism of the cancer. The purpose of this study was to explore the roles of LGALS3 and signaling pathways in the pathogenesis of colorectal cancer. In this study, microarray data GSE8671 were downloaded from the Gene Expression Omnibus database and differentially expressed genes (DEGs) in colorectal cancer were identified by Significant Analysis of Microarray. Gene ontology (GO) analysis was performed on the top 500 upregulated and 500 downregulated genes using DAVID. The signaling pathways were predicted by the signaling pathway impact analysis (SPIA) with pGFdr<0.05 and transcription factors were identified by TFats. The LGALS3-related protein-protein interaction network (PPI) was established by STRING and Cytoscape. In total, 6,593 upregulated and 5,897 downregulated DEGs were identified and 41 downregulated genes, including CLND8 and CLND23 were enriched in cell adhesion. In addition, 21 pathways, such as the cell cycle, p53 signaling pathway and NF-κB signaling pathway, were selected. MYC and TCF7L2 were found to be activated while FOXO3 was suppressed in colorectal cancer. Eight downregulated and 10 upregulated genes were identified in the LGALS3 PPI network. Results of the present study shed new light on the molecular mechanism of colorectal cancer and these findings have the potential to be used in colorectal cancer treatment.