Abstract 1119: Utilization of the TGFβ signaling pathway and cell substrate interaction in a novel anti-cancer drug screen

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Abstract The TGF-β signaling pathway has been demonstrated to play a multifunctional and complicated role in cancer progression, making it an intriguing target for anti-cancer therapeutics. TGF-β signaling drives proliferation of cancer cells, invasion at the tumor periphery, and is associated with metastatic potential in a number of cancer types. Tumors expressing TGF-β activity are positively correlated with poorer prognosis in patients. Complicating the role of TGF-β signaling in cancer progression is that TGF-β signaling leads to distinct cellular responses at different stages of cancer progression. How the same signal transduction pathway drives distinct cellular responses is a critical question. One likely possibility is that TGF-β signaling is highly context dependent. Changes in the tumor microenvironment, as occur during cancer progression, alter the outcome of TGF-β signaling. As an extreme example of how TGF-β signaling is affected by micro-environmental stimuli, we and others previously reported that certain non-cancerous cells on rigid collagen I substrates become sensitized to HGF-induced epithelial scattering in response to TGF-β, while cells on pliant collagen I substrates undergo apoptosis in response to TGF-β. Given that tumors are typically rigid tissues, we sought to define whether cancer cells would respond to TGF-β by undergoing apoptosis when cultured on pliant substrates. We plated a wide variety of cancer cell lines on highly pliant substrates, treated then with TGF-β, and observed cell viability over time. While a number of cells showed no apoptotic response to TGF-β signaling under any condition, we find that a significant number of cancer cells derived from solid tumors respond to TGF-β signaling on pliant substrates by undergoing apoptosis. Another group of cell lines undergo apoptosis on pliant substrates in the absence of any TGF-β stimulation. Reasoning that perturbation of cellular signaling that communicated substrate rigidity to cells might sensitize them to apoptosis in response to TGF-β, we designed a high-content high throughput screen to look for molecules that would induce cells to undergo apoptosis in response to TGF-β signaling. This chemical genetics approach will yield cues into the mechanism of tumor microenvironment sensing, as well as provide lead compounds for development of novel therapeutics Note: This abstract was not presented at the meeting. Citation Format: Wontak Kim, Jacob P. Hoj, Nicholas E. Saguibo, Kendra E. Fullmer. Utilization of the TGFβ signaling pathway and cell substrate interaction in a novel anti-cancer drug screen. [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 1119. doi:10.1158/1538-7445.AM2014-1119