MiR-139 in digestive system tumor diagnosis and detection: Bioinformatics and meta-analysis

Background: Accumulating evidence has indicated that microRNAs play important roles in the initiation and progression of digestive system tumors. However, previous studies suggest that the accuracy of miRNA detection in digestive system tumors was inconsistent. Methods: The candidate miRNAs were obtained from The Cancer Genome Atlas (TCGA). Meta-analysis was performed to evaluate the diagnostic value of these miRNAs in digestive system tumors. Furthermore, the potential target genes of the miRNAs were predicted and assessed with functional analysis. Results: According to TCGA data, miR-139 was a common biomarker of digestive system tumors. It was markedly reduced in tumor tissues as compared with non-cancerous tissues in digestive system tumors. In the meta analysis, the pooled diagnostic odds ratio (DOR) and AUC was 57.51 (95% CI: 14.25-232.04) and 0.96 (95% CI: 0.94-0.97), respectively. Furthermore, the overall sensitivity and specificity was 0.89 (95% CI: 0.73-0.96) and 0.91 (95% CI: 0.75-0.97), respectively. The diagnostic value of tissue miR-139 was higher than the diagnostic value of blood miR-139. In particular, miR-139 was a superior marker for distinguishing colorectal cancer. Conclusion: miR-139 could be a potential biomarker for diagnosis of digestive system tumors especially colorectal cancer.