Stool-Based microRNAs as Potential Non-Invasive Biomarkers for Colorectal Cancer

Abstract

Introduction: Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. MicroRNA (miRNA) dysregulations are associated with various types of human cancers, including CRC. The detection of cancer-related miRNAs in stool samples may become useful diagnostic marker of CRC, because miRNAs in stool samples has high stability, and maintains a high portion of its original level. The aim of this study was to identify stool-based miRNA as non-invasive biomarkers for detection of CRC. Methods: Stool samples were collected from 29 patients with CRC and 29 healthy controls. RNA was extracted from all samples using miRNAeasy Mini Kits. MiRNA levels in stool samples were detected by real-time quantitative reverse transcription PCR. Seven miRNAs were selected on the base on their significant associations with CRC carcinogenesis as reported previously: miR-21, miR-144, miR-135a, miR-92a, miR-106a, miR-200c, and miR-17-3p. The sensitivity and specificity of significantly higher stool miRNAs in CRC were evaluated. Results: The study demonstrated that stool-based miRNAs were stable with highly reproducible detection. Patients with CRC had a significantly higher stool miR-21 level (P=0.018) and miR-92a level (P<0.0001) compared with healthy controls. Stool miR-92a, but not miR-21, was significantly associated with tumor stages. The area under receiver operating characteristic curve (AUROC) for miR-21 was 0.69, with a sensitivity of 79% and specificity of 55%. AUROC for miR-92a was 0.76, with a sensitivity of 76% and specificity of 48%. Conclusion: Stool-based miR-21 and miR-92a may be used as potential non-invasive biomarkers for CRC diagnosis. However, more studies are required to confirm the validity of these miRNAs as valuable non-invasive diagnostic tools for CRC.