Digital PCR for Quantifying Circulating MicroRNAs in Acute Myocardial Infarction and Cardiovascular Disease

Circulating miR-146a expression as a non-invasive predictive biomarker for acute lymphoblastic leukemia

Dysregulation of non-coding microRNAs during the course of tumor development, invasion and/or progression to the distant organs, makes them a promising candidate marker for the diagnosis of cancer and associated malignancies. This exploratory study aims at evaluating the usefulness of plasma concentration of circulating mir-146a as a non-invasive biomarker for acute lymphoblastic leukemia (ALL). Total RNA including miRNA was isolated from 110 plasma samples of patients (n = 66), healthy controls (n = 24) and follow up (n = 20) cases and reverse transcribed. Relative concentrations were assessed using real-time quantitative PCR and fold-change was calculated by 2^−ΔΔCt method. Finally, relative concentrations were correlated to clinicopathological factors. Patients (n = 66) were analyzed to determine fold expression of miR-146a in plasma samples of ALL. Before chemotherapy, pediatric (n = 42) and adult (n = 24) showed overexpression of miR-146a compared with healthy controls (P < 0.0001). There was no effect of age and gender on mir-146a expression in plasma. mirR-146a expression was independent of clinical and hematological features. Moreover, miR-146a levels in plasma of paired samples (n = 20) after treatment showed significant decrease in expression (P < 0.001). Expression of plasma miR-146a may be utilized as non-invasive marker to diagnose and predict prognosis in pediatric and adult patients with ALL. Moreover predicted targets may be utilized for ALL therapy in future.

Liquid biopsy: Circulating exosomal long noncoding RNAs in cancer

Despite many advances in diagnostics and multimodal treatment (surgery, radiotherapy, chemotherapy), cancer still remains one of the most important public health challenges worldwide because of the associated morbidity and mortality. Liquid biopsy has been developed to detect cancer at an early stage based on minimally invasive and serial body fluid tests with the advantage of following tumor evolution in real time. Circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), circulating cell-free noncoding RNAs (cfRNAs) and circulating exosomes represent the major components of liquid biopsy analysis. Liquid biopsy already has been implemented in cancer management, and most studies thus far are mainly focused on CTCs and ctDNA. In fact, the circulating long noncoding RNAs (lncRNAs) in exosomes have been discovered and confirmed to be closely related to tumorigenesis, metastasis and therapy. Thus this review is mainly focused on the clinical potential of circulating exosomal lncRNAs as a source of liquid biopsy biomarkers in cancer diagnosis, prognosis, and response to treatment, offering novel insights into the precision medicine of oncology.