Abstract 2423: Acute in vitro exposure to cigarette smoke particulate matter does not induce epithelial-mesenchymal transition in lung epithelial cells

Abstract

Abstract The epithelial-mesenchymal transition (EMT) program was first identified from studies on embryogenesis and organ development, but has since been found to play vital roles in tissue remodelling and tumorigenesis. EMT is a biological process during which epithelial cells change their morphology to adopt fibroblast-like characteristics. During EMT, cell adhesion is lost while cells become more motile. A number of distinct molecular events are required for a cell to undergo EMT including transcription factor activation, cytoskeletal rearrangement, changes in cell adhesion molecule expression and increased production of extracellular matrix-degrading enzymes. EMT has recently been linked to chronic inflammation and cigarette smoke exposure in the lung and is believed to be involved in lung carcinogenesis. As the specific genes and proteins involved in EMT have been well defined, they can serve as markers to demonstrate the passage of cells through EMT in the context of cigarette smoking. The purpose of this study was to develop an in vitro model of EMT using immortalised human bronchial epithelial (BEAS-2B) cells. EMT was induced in BEAS-2B cells using a 72 hour treatment with 5 ng/mL TGF-β1. Expression of the following EMT markers were assessed at the transcript level using reverse transcription real time-polymerase chain reaction (RT-PCR): alpha smooth muscle actin (α-SMA), collagen 1, fibronectin, vimentin, e-cadherin, slug and snail. Protein levels of α-SMA, fibronectin, β-catenin, e-cadherin and zonular occludin-1 were evaluated using immunocytochemistry techniques. This model was then used to determine the effects of acute (72 hour) cigarette smoke particulate matter treatment on EMT in BEAS-2B cells. Cells were treated with particulate matter alone, and in combination with TGF-β1. Particulate matter did not induce EMT directly, nor did it influence EMT induced by TGF-β1 under the treatment conditions used in this study, based on marker expression. It is possible that a more prolonged exposure to particulate matter is required for EMT induction in BEAS-2B cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2423. doi:1538-7445.AM2012-2423