Abstract 5562: Generation and characterization of highly selective cathepsin S inhibitors with potentials against pancreatic cancer.

Abstract Cathepsin S (CTSS) is a critical cellular protease required for cancer development and metastasis. This proteolytic enzyme is often over-expressed by malignant tumor cells and secreted into the extracellular milieu to degrade surrounding matrix components. Here, we attempted to systematically generate and evaluate potential CTSS inhibitors in hope to identify potent candidates for use as antitumor agents. Detailed kinetic analysis revealed several lead compounds possess very low Ki values and high specificity against target CTSS protease. Results from ECM degradation assays demonstrated that these small molecules could protect fibronectin from CTSS-mediated degradation and consequently hinder tumor cell movement. Treating various pancreatic tumor cell lines with these CTSS inhibitors further resulted in a drastic decrease in cell migration and invasion. The test compounds also reduced the spread of pancreatic tumor cells in orthotopic animal model and thus prolonged mice survival. Finally, these lead molecules exhibited reasonable pharmacokinetic (PK) profiles, suggesting their potential as antitumor agents against pancreatic cancer. Citation Format: Wun-Shaing W. Chang, Chien-Yu Liao, Yi-Hsun Chang, Tzu Chin Wu, Rou-Jhen Wu, Tien-Ning Chang, Jang-Yang Chang, Chun-Cheng Lin. Generation and characterization of highly selective cathepsin S inhibitors with potentials against pancreatic cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5562. doi:10.1158/1538-7445.AM2013-5562