An Air-Liquid Interface Organ-Level Lung Microfluidics Platform for Analysis on Molecular Mechanisms of Cytotoxicity Induced by Cancer-Causing Fine Particles.

Fine particulate matter less than 2.5 μm in diameter (PM2.5) is regarded as a carcinogenic factor, but the mechanism has been left unexplored. Our goal was to reveal the carcinogenic mechanism at the gene and protein level under the inhalational air-liquid interface (ALI) condition. Herein, we developed an ALI organ-level lung microfluidic platform (ALI-OLMP) carrying lung epithelial cell line BEAS-2B and human pulmonary microvascular endothelial cells (HPMEC); the cell viability was above 98% within 14 days on this system, which was used to mimic the practical alveolar microenvironment for the multiomics analysis, to identify the global gene and protein expression after exposure to PM2.5 in Shanghai, China from 2014 to 2015. The combined RNA-Seq and iTRAQ analysis indicated that the unique set was 2532 genes at 10 μg/cm2 of PM2.5, and there were also at least 25 identical activated signal transduction cascades including bladder cancer, transcriptional dysregulation in cancer, the TP53 (p53) signaling pathway, Jak-STAT signaling pathway, and PI3K-Akt signaling pathway, which could lead to blocking of differentiation, cell proliferation and survival, and sustained angiogenesis. The images obtained by the transmission electron microscopy (TEM) showed that the particles could enter the mitochondria, and even get into the nucleus. The Pearson's correlation coefficient test elucidated that inorganics (EC), organics (OC, PAHs, and alkane), and metals (Cr, Mn, and Sb) were significantly correlated to the dysregulated oncoproteins (VEGF, IL6, MDM2, AKT1, STAT, and P53). The findings may to some extent explain the molecular mechanism of carcinogenicity caused by fine-particle exposure.