Molecular expression profiles of selected microRNAs in colorectal adenocarcinoma in patients from south-eastern part of Romania

MicroRNAs (miRNAs) are endogenous, non-coding class of RNAs with functions in the regulation of genes expressions. Dysregulated expressions of miRNAs play important roles in carcinogenesis and cancer progression by targeting various oncogenes and tumor-suppressor genes. miRNAs represent a new field for molecular diagnosis and prognosis of colorectal cancer (CRC) due to their high tissue specificity, their stability, and their dysregulated expression in tumor development. This study aimed to investigate using the qRT-PCR method the expression profile and prognostic value of 11 mature miRNAs in a cohort of 82 Romanian patients diagnosed with CRC. The relationship between the expression levels of selected miRNAs and clinicopathologic features were evaluated using ANOVA and Pearson test. In addition, the receiver operating characteristic (ROC) and area under the curve (AUC) were used to assess the diagnostic values of the miRNAs to discriminate cancerous from non-cancerous states of the samples. The expression levels of miR-30c, miR-144, miR-375, miR-214, and miR-195 in CRC tissue were significantly downregulated (all P < .05; Paired T-Test) than that in normal adjacent tissue sample (NATS), while the expression of miR-141, miR-182, miR-183, miR-21, and miR-370 in CRC tissue were significantly upregulated (all P < .001) than that in NATS. Moreover, the expression levels of miR-182, miR-183, miR-141, and miR-21 were demonstrated to be associated with a gradual increase in fold change expression with depth of tumor invasion (all P < .05), lymph node invasion (all P < .001), and maximal increase with distant metastasis (all P < .001). Moreover, the analysis of ROC curves revealed that AUC (95% CI) of miR-182, miR-183, miR-141, and miR-21 in diagnosis of CRC was 0.76 (0.66–0.87), 0.85 (0.78–0.94), 0.77 (0.62–0.92), 0.83 (0.73–0.90), respectively. The univariate and multivariate Cox-proportional hazard regression for all variables revealed that the nodal status, distant metastasis, miR-21, miR-141, miR-182, and miR-183 were independent prognostic markers of CRC. In conclusion, altered expressions of miR-21, miR-141, miR-182, and miR-183 in CRC varies at different stages of CRC development and may serve as potential diagnosis molecular biomarkers in Romanian patients with CRC. Further investigations are needed to confirm our findings.