Epithelial-mesenchymal transition effect of fine particulate matter from the Yangtze River Delta region in China on human bronchial epithelial cells

Abstract

Epidemiological studies have demonstrated that fine particulate matter (PM2.5) exposure causes airway inflammation, which may lead to lung cancer. The activation of epithelial–mesenchymal transition (EMT) is assumed to be a crucial step in lung tumor metastasis and development. We assessed the EMT effect of low concentrations (0, 0.1, 1.0, and 5.0μg/mL) of PM2.5 organic extract on a human bronchial epithelial cell line (BEAS-2B). PM2.5 samples were collected from three cities (Shanghai, Ningbo, and Nanjing) in the Yangtze River Delta (YRD) region in autumn 2014. BEAS-2B cells were exposed to the PM2.5 extract to assess cell viability, invasion ability as well as the relative mRNA and protein expressions of EMT markers. Our findings revealed that BEAS-2B cells changed from the epithelial to mesenchymal phenotype after exposure. In all groups, PM2.5 exposure dose-dependently decreased the expression of E-cadherin and increased the expression of Vimentin. The key transcription factors, including ZEB1 and Slug, were significantly up-regulated upon exposure. These results indicated that the PM2.5 organic extract induced different degrees of EMT progression in BEAS-2B cells. The cell invasion ability increased in a concentration-dependent manner after 48hr of treatment with the extract. This study offers a novel insight into the effects of PM2.5 on EMT and the potential health risks associated with PM2.5 in the YRD region.