Assessment of Serum MicroRNA-21 Gene Expression for Diagnosis and Prognosis of Colorectal Cancer

Background MicroRNAs (miRNAs) are small, non-coding RNAs that are involved in carcinogenesis through posttranscriptional gene regulatory activity. The current study aimed to evaluate serum miR-21 expression levels as potential biomarkers for diagnosis and prognosis of colorectal cancer (CRC) patients. Methods Quantitative real-time RT-PCR was applied to determine the relative expression level of miR-21 in serum. At the same time, the sensitivity and specificity of this marker were evaluated by receiver operating characteristic (ROC) curve analysis. Results miR-21 expression levels of serum were 3.4 and 1.25 in patient and control, respectively (p < 0.05). The sensitivity and specificity of miR-21 were found to be 95.8% and 91.7%, respectively. The high expression level of serum miR-21 were associated with higher local recurrence, TNM staging, PT staging, venous invasion, liver metastasis, and recurrence (p < 0.05). Conclusion The results of this study indicated that miR-21 expression levels in serum can be considered as a novel non-invasive biomarker for early detection and prognosis of CRC patients.