BACKGROUND: Colorectal cancer (CRC) is one of the most common malignancies worldwide, with high morbidity and mortality rates. The purpose of this study was to identify potential biomarkers in the progression of CRC.

MATERIAL AND METHODS: Gene and isoform expression datasets of CRC was downloaded from The Cancer Genome Atlas (TCGA). EBSeq of R was used for the normalization of gene and isoform expression, as well as the identification of differential expression genes (DEGs) and isoforms (DEIs) of CRC samples compared with normal samples. The enriched functions of DEGs and DEIs were obtained based on the Database for Annotation, Visualization and Integrated Discovery (DAVID). An independent dataset, GSE38832, was downloaded from the Gene Expression Omnibus (GEO) database for survival analysis of genes with sustained decreased/increased expression values at both gene and isoform levels with the development of CRC.

RESULTS: A total of 2301 genes and 4241 isoforms were found to be significantly differentially expressed in stage I–IV CRC samples. They are closely associated with muscle or cell system activity. Sixteen genes were screened out with sustained decreased/increased expression values at both gene and isoform levels with the development of CRC. Aberrant CBX8 and CD96 expressions were found to be significantly associated with CRC survival.

CONCLUSIONS: Through combined analysis of gene and isoform expression profiles, we identified several potential biomarkers that may play an important role in the development of CRC and could be helpful in its early diagnosis and treatment.

Keywords: Colorectal Neoplasms, Protein Interaction Maps