Early detection and staging of colorectal cancer using a panel of micro RNAs

Abstract

Purpose: To improve lymph node (LN) staging in patients with colon cancer (CC). The present study describes the selection of CC-specific miRNAs and assesses their utility as a micro metastases detection assay. Methods: 30 miRNAs have been selected from a microarray assay and 16 miRNAs from database mining for their specific upregulation in colon cancer tissues as compared to normal adjacent tissues. Differential expression was validated by RT-qPCR in a larger cohort of samples (n=20) and compared to normal lymphatic tissues (n=6) and normal peripheral blood lymphocytes (PBLs, n=14). The selected miRNA panel was then used for the screening of 84 lymph nodes (LN) obtained from colon cancer patients (n=20) Results: After validation, a panel of 8 miRNAs was found to be significantly upregulated in CC compared to normal adjacent tissues and to normal lymphatic tissues: miR-96, miR-183, miR-194, miR-200a, miR-200b, miR200c, miR-203 and miR-429. A total of 84 LNs were analysed: 12 LN metastases were detected by H&E, 18 by CK staining whereas 32 were detected by the CC-specific miRNA analysis. This represents an increase of 40% in the detection rate. Conclusion: This study demonstrated the ability of a CC-specific 8 miRNA panel in detecting micro metastases in CC patients.