Exosomes from PM^(2.5)-treated Human Bronchial Epithelial Cells Increase Lung Cancer Metastatic Potential

Objective Fine particulate matter(PM^(2.5))is an air pollutant that has become of great concern in recent years.Numerous studies have found that PM^(2.5)may contribute to lung cancer,but the pathogenesis has not yet been fully elucidated.In this study,we explored the roles of exosomes from bronchial epithelial cells in PM^(2.5)-promoted lung cancer metastasis.Methods Exosomes were isolated from cell supernatants.An animal model of lung metastasis(established by tail vein injection of A549-luc)and in vitro studies with lung cancer cell lines were used to investigate the effects of exosomes derived from PM^(2.5)-treated human bronchial epithelial cells(PHBE-exo).Results The animal experiments revealed that PHBE-exo-treated mice showed stronger luciferase activity and a larger relative metastatic region in the lungs,thus indicating that PHBE-exo promoted the metastatic potential of lung cancer.Additionally,PHBE-exo promoted the migration,invasion and epithelial-to-mesenchymal transition of lung cancer cells,in a manner mediated by activation of c-Jun Nterminal kinase.Conclusion These results implied that PM^(2.5)may promote the development of lung cancer through exosomes derived from bronchial epithelial cells,thus providing a potential interventional target for lung cancer.These findings broadened our understanding of cancer-promoting mechanisms of environmental pollutants.