A Novel Circulating microRNA Signature Panel as a Prognostic Biomarker for in Patients with Colorectal Cancer

BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide, necessitating the development of reliable prognostic biomarkers. Circulating microRNAs (miRs) have emerged as promising, non-invasive biomarkers. This study was designed as a comprehensive evaluation, conducted in two independent stages, to identify circulating miRs capable of providing an accurate prognosis of CRC. SUBJECTS: The study included 225 subjects (150 Egyptian CRC patients and 75 healthy controls). We selected 25 miRs based on recent studies and our previous work and evaluated their expression in the Evaluation Group (65 subjects). The miRs showing significant differential expression were further confirmed in the Validation Group (160 subjects: 110 CRC patients and 50 controls). For all samples, miRNAs were extracted, and their concentration, integrity, and purity were measured using a NanoDrop, followed by cDNA synthesis and qRT-PCR analysis. RESULTS: The serum levels of eight miRNAs (Let-7c, miR-21, miR-26a, miR-26b, miR-126, miR-146a, miR-223, and miR-374) were significantly higher in CRC patients and were able to discriminate between CRC patients and healthy controls. The combined analysis of all eight miRNAs showed higher specificity, with an AUC of 0.92 and a specificity of 99.73% for CRC patients. The combination of five miRNAs, which exhibited a greater fold change in CRC patients, achieved an AUC of 0.97 and a specificity of 99.6%. In contrast, the combination of miR-21, miR-26a, and miR-26b demonstrated the highest AUC value of 0.974, with a specificity of 99.27%. Computational analysis revealed that CCND1 and TP53 function dually as efficacy and prognostic biomarkers for CRC, and that these roles are regulated by let-7a-5p. Collectively, the data indicate that this novel miRNA signature panel improves prognostic accuracy compared to individual miRNA analysis and may support enhanced patient screening and personalized treatment strategies in CRC. CONCLUSION: We established a circulating miRs signature panel for the first time to accurately predict the prognosis of Egyptian CRC patients.