Environmentally Persistent Free Radical Promotes Lung Cancer Progression by Regulating the Expression Profile of miRNAs.

Background: Environmentally persistent free radicals (EPFRs) are generated in the combustion processes of solid waste and can cause adverse influences on human health, especially lung diseases. Lung cancer is one of the most serious malignancies in recent years, which the global deaths rate is about 1.6 million every year. Methods and Results: In this study, we verified that ZnO/MCB EPFRs promote cell proliferation and migration, impedes cell apoptosis in lung cancer. Furthermore, we found that ZnO/MCB could influence the expression of miRNAs (miR-18a and miR-34a). In vivo, ZnO/MCB and ZnO EPFRs can reduce the weight and survival rate of BALB/c male mice more than that of BALB/c female mice. In the ZnO/MCB exposed group, male mice lung became even smaller, while the female mice the lung increased significantly. Taken together, our results provide evidence for assessing the potential health risks of persistent free radicals on fine particles. Conclusions: This study linked toxicity of EPFRs with miRNAs revealed the potential health hazard to human lung cancer.