Gene expression profile comparison between colorectal cancer and adjacent normal tissues

The present study aimed to compare gene expression profiles between colorectal cancer and adjacent normal tissues, and to perform a preliminarily analysis of the key genes and underlying molecular mechanisms implicated in colorectal cancer development. Gene expression microarray chips were used to screen genes that were differently expressed between colorectal cancer and adjacent normal tissues. Approximately 1,183 genes were differentially expressed in cancer tissues compared with adjacent normal tissues (P≤0.05; fold difference, >2.0), of which 570 genes were upregulated and 613 genes were downregulated. In total, 6 upregulated genes, including keratin 23, collagen type X α1, collagen type XI α1, cell migration-inducing hyaluronan-binding protein, transforming growth factor-β1 and V-Myc avian myelocytomatosis viral oncogene homolog, and 2 downregulated genes, including channel α subunit 7 and EPH receptor A7, were selected and validated using reverse transcription-quantitative polymerase chain reaction, which exhibited results that were consistent with the microarray analysis. These 1,183 differentially expressed genes were further classified into 71 groups based on their functions using gene ontology and pathway analyses. Kyoto Encyclopedia of Genes and Genomes analysis of these upregulated or downregulated genes suggested that 23 signaling pathways were involved. The present study preliminarily screened for and identified key genes and signaling pathways that may be closely associated with colorectal cancer development. However, subsequent gene function studies are required to verify these findings.