Abstract 1298: Designing novel small molecule inhibitors as possible targeted therapeutics to prevent breast cancer metastasis

Abstract Breast cancer is currently the second leading cause of cancer-related deaths and the most commonly diagnosed cancer among women in the Unites States. Localized breast cancer has a five-year survival rate of 99%, however the survival rate for patients with distant metastasis is 27%, despite improved screening and detection methods. Currently, there are few targeted therapies that specifically inhibit metastasis. Research performed by our lab and others has shown that inflammatory cytokines play a crucial role in promoting cancer growth and metastatic potential in cancer cells. While efforts have been made to develop FDA approved therapeutics for inflammatory cytokines, very few have successfully made it through clinical trials and several cytokines still lack effective clinical inhibitors. Our research has developed a stepwise approach towards designing and testing novel small molecule inhibitors (SMIs) against inflammatory cytokines. In silico computational screening of compound libraries towards specific inflammatory cytokines revealed potential molecules that interact with receptor binding regions and inhibit cytokine biological function. Top candidate inhibitors were analyzed for direct interaction with cytokines using differential scanning fluorimetry, fluorescent quenching, and Chemical Shift Pertubation NMR (CSP-NMR). Additionally, to quantitatively measure cytokine-receptor interference, a novel ligand-receptor binding assay was developed highlighting small molecule inhibitors that effectively prevent biological cytokine function. In vitro efficacy of the SMIs were analyzed by measuring inhibition of various signaling cascades activated by inflammatory cytokines using enzyme-linked immunosorbent assay (ELISA) and immunoblot assays. Inhibition of tumor cell proliferation, epithelial to mesenchymal transition (EMT), and cytokine-induced secretion of pro-tumorigenic molecules was also assessed. From these in silico and in vitro methods, SMI's are structurally modified with effective functional groups to increase efficacy of binding interaction and reduce toxicity for living systems. Finally, small molecule inhibitors that have been sufficiently tested for efficacy are then examined in vivo to evaluate toxicity and determine the maximum tolerated dose. SMI's that prove to be non-toxic are evaluated further in vivo by mouse mammary breast cancer models to analyze reduction of distant metastases. Our interdisciplinary team has designed, synthesized, and tested small molecule inhibitors (SMIs) to target inflammatory cytokines shown to promote metastasis in cancer with the long-term goal of understanding lethal breast cancer metastasis, as well as providing a novel FDA approved therapeutic for breast cancer patients. Citation Format: Cody L. Wolf, Clyde Pruett, Darren Lighter, Cooper McGrath, Amberlyn Nemeth, Joey Tuccinardi, Grace Coughlin, Samuel Randall, Joey Day, Matthew King, Lisa Warner, Don Warner, Cheryl L. Jorcyk. Designing novel small molecule inhibitors as possible targeted therapeutics to prevent breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1298.