Drug abuse is one of the most severe global social and public health problems, especially in China. However, objective blood biomarkers that are easy to detect are still in great need. This study was aim to explore the expression pattern of circulating microRNAs (miRNAs) in subjects with drug addiction and test the potential of altered serum miRNAs as noninvasive diagnostic tools for drug abuse.
Serum samples were obtained from 42 heroin abusers, 42 methamphetamine (MA) abusers and 42 controls. Microarray-based miRNA analysis was first applied to screen unique serum miRNA profiles in drug abusers on a training set of serum samples from 12 heroin abusers, 12 MA abusers and 12 control subjects. The expression levels of selected candidate miRNAs were subsequently verified in individual samples of the training set and further confirmed independently in a validation set of samples from 30 heroin abusers, 30 MA abusers and 30 controls using real-time quantitative polymerase chain reaction (RT-qPCR).
Microarray analysis identified 116 and 109 significantly altered miRNAs in heroin abusers and MA abusers, respectively. Three miRNAs, including let-7b-5p, miR-206 and miR-486-5p, were verified to be significantly and steadily increased in heroin abusers, and miR-9-3p was significantly increased in MA abusers compared with normal controls. The areas under the curve (AUCs) of the ROC curve of these miRNAs ranged from 0.718 to 0.867.
Our study raises the possibility that the altered serum miRNAs could potentially be used as an auxiliary tool to identify individuals in drug abuse and addiction.

Copyright © 2020 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.