Abstract 166: Transcriptional control of epithelial-mesenchymal transition in the context of changing tumor microenvironment
Authors: Tuttle Kevin , Grant Adam , Barlow Ryan , Johnson Evan , Hansen Marc D. 
Published: May 2015

The ability of cancer cells to detach from their neighbors, invade through local tissues, and establish distant metastases is a major contributor to cancer mortality. Epithelial-mesenchymal transition (EMT) describes a developmental process by which cells break cell-cell adhesions and gain motility. The interaction between a cancer cell and the tumor microenvironment is emerging as a critical component of this process. EMT is triggered by a number of cellular signaling pathways that can be modulated by the properties of the surrounding extracellular matrix (ECM). Defining how genetic networks regulate cellular signaling in response to changes in ECM interactions would allow design of treatment strategies that target the tumor microenvironment in order to halt cell invasion.

Transcriptome sequencing on MDCK cells, a tissue culture model system that undergoes EMT in response to HGF stimulation, can be used to define how changes in gene expression drive the cellular events of metastasis. Since these cells can be grown on different ECM substrates, how cellular signaling is altered by substrate composition can be determined. Through differential expression analysis of a time-series, a timeline for the transcriptional events that drive metastasis can be established. Comparing the timeline of transcriptional events on different substrates will determine the contribution of regulatory pathways associated with conditions where the ECM alters EMT. In short, differential expression analysis of HGF-stimulated MDCK cells will define, one, a timeline for the changes in gene expression that drive EMT and, two, the differences in gene expression between substrates that are responsible for their ability to affect EMT.

Being a well-characterized model for EMT makes MDCK cells an attractive model for studying cancer metastasis. Validation of findings in this line will be confirmed in a panel of human cancer cell lines. This can be done by comparing phenotypic and molecular (transcriptional and protein level) changes associated with EMT in MDCK cells to those of EMT in HepG2 cells. The cell lines’ morphological changes and actin rearrangement can be compared using live cell imaging and fluorescence microscopy techniques. In addition, a panel of genes/proteins that are up- or down-regulated during EMT can be used to compare the two lines at the molecular level using qPCR and Western blotting. This has the additional advantage of further characterizing the MDCK model and demonstrating its utility for understanding transcriptional events in EMT more generally.

Citation Format: Kevin Tuttle, Adam Grant, Ryan Barlow, Evan Johnson, Marc D. Hansen. Transcriptional control of epithelial-mesenchymal transition in the context of changing tumor microenvironment. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 166. doi:10.1158/1538-7445.AM2014-166