Novel miRNAs as potential biomarkers in stage II colon cancer: microarray analysis

The aim of this study was to determine oncogenic and tumor-suppressing miRNA profiles associated with the development and progression of cancer using tumor tissues from patients with colorectal cancer (stage II) that did not show nodal spread or advanced metastasis to identify potential biomarkers. A microarray system (GeneChip miRNA 4.0 Array chip, Affymetrix) was used to determine the microRNA profiles of five patients with stage II colon cancer based on normal and colon tumor tissues. Of 32 identified miRNAs, an increase in three microRNAs (hsa-miR-4745-5p, hsa-miR-6126, and hsa-miR-1469) was observed in tumor tissues relative to that in control tissues. Additionally, this study demonstrated for the first time that the expression of the 8 miRNAs (hsa-miR-378i, hsa-miR-378a-3p, hsa-miR-378c, hsa-miR-378d, hsa-miR-378e, hsa-miR-378f, hsa-miR-378a-5p, and hsa-miR-378g) from miR-378 members among the differentially expressed miRNAs is reduced. The target genes of these downregulated miRNAs were determined by using DIANA miRPath v3. The effect of identified genes on colon cancer stage II was determined the biological process and biological pathway using Funrich Gene Enrichment. It was revealed that these miRNAs were affected the signaling pathways which control cell proliferation, cell-cell interaction, and apoptosis in stage II colon cancer. In patients with early stage II colon cancer, miR-378 can be used as a biomarker of colorectal cancer. Thus, miR-378 can facilitate treatment with early diagnosis.