miR-3065-5p and miR-26a-5p as Clinical Biomarkers in Colorectal Cancer: A Translational Study.

Background/Objectives: The prognosis of colorectal cancer (CRC) is mainly based on the clinical stage; however, CRC is considered a complex disease due to its molecular heterogeneity. The development of novel biomarkers to improve patients' diagnosis and prognosis remains fundamental. Methods: A cohort of forty-nine CRC patients from the National Cancer Institute of Mexico was included to collect clinical and miRNA expression data. The expression of a group of miRNAs was compared between CRC and non-tumoral adjacent tissues. Prognosis assessment considering each miRNA expression was tested using Kaplan-Meier survival curves and Cox regressions. Statistical significance was defined as p ≤ 0.05. Trial registration: Retrospective study No.2021/046. Results: miR-3065-5p and miR-26a-5p expression differed between non-tumoral adjacent and tumoral tissues (p = 0.02). In terms of overall survival (OS), patients with low expression of miR-3065-5p had a median OS of 70 months, while patients with high levels did not reach the median OS (p = 0.041). Male patients with low expression of this miRNA had an OS of 70 months, whereas patients with high levels did not reach the median OS (p = 0.050). Under uni-multivariate analysis, clinical stage (HR: 1.30, CI 1.23-2.30; p: 0.001) and low levels of miR-3065-5p (HR: 1.30, CI 1.23-2.30; p: 0.001) were determined as predictor factors of OS. To this end, we designed the "Prognosis miRNAs assessment in cancer" (PROMIR-C) algorithm, which integrated clinical features with miR-3065-5p expression levels. Conclusions: These findings support the clinical utility of miR-26a-5p and miR-3065-5p in the diagnosis and prognosis of CRC. PROMIR-C is a fundamental tool for clinicians in treatment decision-making, prognosis assessment, and outcome of CRC.