Circulating levels of the miRNAs, miR-194, and miR-29b, as clinically useful biomarkers for colorectal cancer

The microRNAs (miRNAs), miR-194 and miR-29b, have been shown to downregulate in colorectal cancer (CRC) and may identify and classify CRC patients as compared with those in control subjects. In the current study, we aimed to explore whether the serum levels of the miRNAs could be potential biomarkers for diagnosis and prognosis of CRC. A quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assay was utilized to determine and compare serum levels of miR-194 and miR-29b in 55 patients with CRC and 55 control subjects. The correlations between levels of the miRNAs and clinicopathological stages of cancer were analyzed in patients. Receiver operating characteristic (ROC) curve and survival analyses were carried out, respectively, to determine diagnostic and prognostic values of the miRNAs. Serum levels of miR-194 and miR-29b were found to be significantly lower in CRC patients than those in control subjects (P < 0.0001). Moreover, serum levels of the miRNAs in patients were inversely correlated with the advanced TNM stages (P = 0.01). ROC curve and survival analyses revealed that reduced levels of the miRNAs could serve as diagnostic and prognostic biomarkers for patients with CRC (P = 0.0001). Serum levels of miR-194 and miR-29b may serve as potential biomarkers for diagnosis and prognosis of CRC.