Identification and development of novel Wnt/β-catenin signalling inhibitors

With an ever-aging population the risk of developing cancer is greater than ever. The WNT/β catenin signalling pathway has been highlighted as a key pathway in cancer development and furthermore, is an attractive therapeutic target. However, the number of drugs targeting β-catenin is limited due to various factors and claimed small molecule modulators often have inherent problems in specificity of mode of action or a lack of evidence, biophysical, K_D, crystallography or otherwise. Therefore, there is dire need for therapeutic intervention of β-catenin. In this thesis, we review the literature of reported and putative β-catenin inhibitors and highlight the vast majority of them are flagged by computational filters such as PAINs and Brenk filters. Furthermore, we investigate these reported inhibitors by biophysical methods such as Differential Scanning Fluorimetry (DSF) and Isothermal Titration Calorimetry (ITC) and show that in our hands none of them engage with recombinant purified β-catenin. Herein we report the discovery of novel small fragments that are β-catenin stabilisers. These fragments have been validated by orthogonal biophysical techniques such as DSF and Saturation Transfer Difference Nuclear Magnetic Resonance (STD-NMR) and ITC. Furthermore, we report the synthesis of Carnosic acid derivatives as novel βcatenin destabilisers. Finally, we undertake in silico HTVS to identify top computational compounds to test against β-catenin in vitro.