Up-regulation of exosomal miR-125a in pneumoconiosis inhibits lung cancer development by suppressing expressions of EZH2 and hnRNPK

Exposure to nanoparticles may lead to pneumoconiosis and lung cancer; however, whether patients suffering from pneumoconiosis also face a high risk of lung cancer has been under debate for decades. Recently, exosomes have been found to play critical roles in many diseases via intercellular cargo transportation, which has provided a new insight into the mechanistic investigation of nanoparticle-induced respiratory disorders. Herein, we isolated exosomes from the venous blood of patients with pneumoconiosis and healthy controls and then, we profiled the expression signatures of exosomal miRNAs using high-throughput sequencing technology. A total of 14 aberrantly expressed miRNAs were identified and used to process target gene prediction and functional annotation. Specially, miR-125a along with its target genes EZH2 and hnRNPK was found to play a significant role in the development of lung cancer. We then adopted a series of cellular experiments to validate the role of miR-125a in lung cancer. From the results obtained, we found that the suppression of EZH2 and hnRNPK by high levels of miR-125a inhibited the development of nanoparticle-induced lung adenocarcinoma, which contributed to the clarification of the relation between pneumoconiosis and lung cancer.