Abstract C54: Characterization of HGF-mediated EMT and its inhibition with novel HGF pathway inhibitors using transcriptomic analysis

Abstract

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. Interestingly, cells generated by EMT also bear stem cell properties and are more resistant to chemotherapeutics. EMT is triggered by a number of cellular signaling pathways, including via hepatocyte growth factor. Inappropriate signaling in epithelial tumors is thought to drive EMT, facilitating cancer metastasis. A common feature is the activation of a number of transcriptional programs. Here we report the results of transcriptomic studies that are designed to characterize transcriptional changes in cells undergoing EMT in response to HGF stimulation. MDCK cells, a normal epithelial cell line, were stimulated with HGF for different amounts of time under otherwise identical culture conditions. Since cell substrate composition affects the robustness of the HGF response, we performed this experiment on cells grown on different extracellular matrices in an attempt to better understand how cellular substrates provide context to HGF signaling. Triplicate samples of mRNA were generated from these cultures for transcriptomic sequencing and analysis. Each sample generated 20-40 million sequence reads that were assembled into known and de novo (novel) transcripts using Tuxedo Suite, allowing detection of differential transcript expression by cummeRbund and edgeR. Many of the differentially expressed genes correlated well to known cancer pathways. HGF signaling is widely accepted to play an important role in cancer progression and to be an important target for development of novel therapeutics. We previously identified a series of novel HGF pathway inhibitors using a phenotypic screening approach. Compounds were subjected to analysis of their structure-activity relationship, in vivo toxicity, and pharmacokinetic profiles. Compounds that block EMT without affecting proliferation were applied to MDCK cells prior to HGF stimulation and mRNA samples generated from these cultures. We report how these inhibitors alter the transcriptional response of MDCK cells to HGF stimulation, providing a molecular basis for how these inhibitors prevent EMT. Citation Format: Kevin J. Tuttle, Jason Burton, W Evan Johnson, Marc DH Hansen. Characterization of HGF-mediated EMT and its inhibition with novel HGF pathway inhibitors using transcriptomic analysis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C54.