Clinical significance of circulating miR-126 quantification in malignant mesothelioma patients

ObjectivesAim of this study was to evaluate the accuracy and precision of the detection of individual miRNA as clinical biomarkers in the serum.Design and methodsmiRNA-126 was quantified in serum using endogenous and exogenous controls for normalization and the accuracy and precision of the method evaluated. The diagnostic value of serum miRNA-126 was evaluated in malignant mesothelioma (MM) and non-small-cell lung cancer (NSCLC) patients using both relative and absolute qRT-PCR methods.ResultsThe use of endogenous invariant and exogenous synthetic controls as well sample dilution markedly improves the accuracy and precision of the assay. The inter- and intra-assay analyses revealed that relative qRT-PCR is a more reliable method. Circulating miR-126 detected in the serum by relative qRT-PCRs was found low-expressed in both malignancies, significantly differentiated MM patients from healthy controls and NSCLC from MM, but do not discriminate NSCLC patients from control subjects. Kaplan–Meier analysis revealed that low level of circulating miR-126 in MM patients was strongly associated with worse prognosis.ConclusionsWe propose that this approach can be adopted for accurate analysis of other suitable circulating miRNA markers of different types of cancer.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Relative qRT-PCR detects circulating miRNAs with the confidentiality interval < 5%. ► Endogenous and exogenous control normalization improve the precision of the assay. ► The sample dilution enhances miRNA extraction reducing the coefficient of variation. ► Circulating miRNA-126 represent a sensitive diagnosis and prognosis marker for MM.