A putative molecular network associated with colon cancer metastasis constructed from microarray data

BACKGROUND This study aimed to identify the potential molecular network associated with colon cancer metastasis. METHODS A gene expression profile dataset (GSE40367) downloaded from Gene Expression Omnibus was used to identify and compare differentially expressed genes (DEGs) between primary colon adenocarcinoma tissues and matched tissue samples of liver metastases of colon adenocarcinoma. After the functional analysis of the DEGs, their protein-protein interactions (PPIs) were analyzed, and the transcription factors (TFs) and microRNAs (miRNAs) that regulated these DEGs were predicted. The data were used to construct an integrated network of DEGs, TFs, and miRNAs. Finally, the GSE68468 dataset was used to validate the DEGs associated with liver metastasis of colon adenocarcinoma identified in the GSE40367 dataset. RESULTS Compared with the primary colon adenocarcinoma sample, 262 DEGs were upregulated and 216 were downregulated in the liver metastasis sample. The DEGs were primarily involved in functions associated with cell junctions and cell adhesion. The DEGs included 17 genes encoding TFs, and 39 miRNAs that regulated DEGs were predicted. Further analysis of the DEGs led to the identification of 490 PPIs. The data were used to construct an integrated network consisting of DEGs, TFs, and miRNAs. DEGs with a high degree of connectivity in the network included FGF2, ERBB4, PTPRC, CXCR4, CCL2, and CCL4. The network also revealed that FGF2 interacted with ERBB4, PTPRC, and CXCR4 and that PTPRC interacted with CXCR4. Furthermore, LCP2 and APBB1IP were predicted to target several other DEGs, including PTPRC, and miR-30a-3p and miR-30e-3p were predicted to regulate ERBB4 and several other DEGs. Notably, FGF2, ERBB4, PTPRC, LCP2, CCL2, and CCL4 were also identified as DEGs in the GSE68468 dataset. CONCLUSION The DEGs, TFs, and miRNAs identified in this study might play key roles in colon cancer metastasis.