Abstract
Colorectal cancer (CRC) is the fourth most commonly diagnosed cancer and one of the leading causes of cancer death worldwide. Despite diagnostic and therapeutic advances, CRC mortality remains high, especially in industrialized countries. Numerous studies have highlighted the pathogenetic role of altered microRNA (miRNA) expression among the various factors contributing to the development and progression of colorectal cancer (CRC). However, the data regarding specific miRNAs involved in CRC pathogenesis remain inconsistent, and no miRNAs have been recognized so far as reliable or effective biomarkers for the diagnosis of this tumor type. To identify novel miRNA biomarkers in CRC, this study validated the expression levels of a four-miRNA signature predicted to be involved in CRC by analyzing both tissue and liquid biopsy samples. Our experimental and bioinformatics results highlighted the diagnostic potential of hsa-miR-21-5p, hsa-miR-503-5p, and hsa-miR-375, as well as the potential prognostic value of hsa-miR-497-5p overexpression and hsa-miR-375-3p downregulation. Overall, the results obtained suggest the diagnostic and prognostic significance of this four-miRNA signature in CRC.