A miRNA Signature for Non-Invasive Colorectal Cancer Diagnosis in Morocco: miR-21, miR-29a and miR-92a.

Colorectal cancer (CRC) is the third most diagnosed cancer and a leading cause of cancer-related mortality in Morocco, often detected at late stages. Circulating microRNAs (miRNAs) have emerged as promising non-invasive biomarkers for CRC detection, with miR-21, miR-29a, and miR-92a showing significant diagnostic potential. This study aimed to evaluate the expression levels of these miRNAs in a Moroccan population and their efficacy as diagnostic biomarkers.

Methods: A prospective study was conducted using blood samples from 50 CRC patients and 50 healthy controls. Circulating miRNA expression levels were quantified through reverse transcription quantitative PCR (RT-qPCR), with normalization to miR-1228-3p. Statistical analyses, including the Mann-Whitney U test, Receiver Operating Characteristic (ROC) curve analysis, sensitivity (Sen), and specificity (Spe) evaluations, were performed to assess the diagnostic accuracy of individual miRNAs and their combined performance as panels.

Results: The expression levels of miR-21, miR-29a, and miR-92a were significantly elevated in CRC patients compared to healthy controls (all p < 0.001). ROC analysis demonstrated that miR-92a exhibited the highest individual diagnostic performance (AUC: 0.938), followed by miR-21 (AUC: 0.907) and miR-29a (AUC: 0.898). Sensitivity and specificity were 88% and 90%, 92% and 56%, and 76% and 94%, respectively. Combinatorial analysis revealed that the miR-29a and miR-92a panel achieved the highest diagnostic accuracy (AUC: 0.976), surpassing individual miRNAs and other combinations, highlighting its potential as a robust, non-invasive biomarker panel for CRC.

Conclusions: This study highlights the potential of the miR-29a and miR-92a combination, which achieved excellent diagnostic efficiency (AUC: 0.976). These findings underscore miRNA utility in enhancing early detection and reducing CRC-related mortality in Morocco.