Discovering cell-active BCL6 inhibitors: effectively combining biochemical HTS with multiple biophysical techniques, X-ray crystallography and cell-based assays

DOI: 10.1038/s41598-022-23264-z

Authors: Olivier A. Pierrat (The Institute of Cancer Research) , Manjuan Liu (The Institute of Cancer Research) , Gavin W. Collie (The Institute of Cancer Research) , Kartika N. Shetty (The Institute of Cancer Research) , Matthew J. Rodrigues (The Institute of Cancer Research) , Yann-Vai Le Bihan (The Institute of Cancer Research) , Emma A. Gunnell (The Institute of Cancer Research) , P. Craig Mcandrew (The Institute of Cancer Research) , Mark Stubbs (The Institute of Cancer Research) , Martin G. Rowlands (The Institute of Cancer Research) , Norhakim Yahya (The Institute of Cancer Research) , Erald Shehu (The Institute of Cancer Research) , Rachel Talbot (The Institute of Cancer Research) , Lisa Pickard (The Institute of Cancer Research) , Benjamin R. Bellenie (The Institute of Cancer Research) , Kwai-Ming J. Cheung (The Institute of Cancer Research) , Ludovic Drouin (The Institute of Cancer Research) , Paolo Innocenti (The Institute of Cancer Research) , Hannah Woodward (The Institute of Cancer Research) , Owen A. Davis (The Institute of Cancer Research) , Matthew G. Lloyd (The Institute of Cancer Research) , Ana Varela (The Institute of Cancer Research) , Rosemary Huckvale (The Institute of Cancer Research) , Fabio Broccatelli (The Institute of Cancer Research) , Michael Carter (The Institute of Cancer Research) , David Galiwango (The Institute of Cancer Research) , Angela Hayes (The Institute of Cancer Research) , Florence I. Raynaud (The Institute of Cancer Research) , Christopher Bryant (The Institute of Cancer Research) , Steven Whittaker (The Institute of Cancer Research) , Olivia W. Rossanese (The Institute of Cancer Research) , Swen Hoelder (The Institute of Cancer Research) , Rosemary Burke (The Institute of Cancer Research) , Rob L. M. Van Montfort (Institute of Cancer Research)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 12

State: Published (Approved)
Published: November 2022

Abstract: By suppressing gene transcription through the recruitment of corepressor proteins, B-cell lymphoma 6 (BCL6) protein controls a transcriptional network required for the formation and maintenance of B-cell germinal centres. As BCL6 deregulation is implicated in the development of Diffuse Large B-Cell Lymphoma, we sought to discover novel small molecule inhibitors that disrupt the BCL6-corepressor protein–protein interaction (PPI). Here we report our hit finding and compound optimisation strategies, which provide insight into the multi-faceted orthogonal approaches that are needed to tackle this challenging PPI with small molecule inhibitors. Using a 1536-well plate fluorescence polarisation high throughput screen we identified multiple hit series, which were followed up by hit confirmation using a thermal shift assay, surface plasmon resonance and ligand-observed NMR. We determined X-ray structures of BCL6 bound to compounds from nine different series, enabling a structure-based drug design approach to improve their weak biochemical potency. We developed a time-resolved fluorescence energy transfer biochemical assay and a nano bioluminescence resonance energy transfer cellular assay to monitor cellular activity during compound optimisation. This workflow led to the discovery of novel inhibitors with respective biochemical and cellular potencies (IC50s) in the sub-micromolar and low micromolar range.

Journal Keywords: Biochemistry; Biophysical chemistry; Cancer; Drug discovery; Oncology; Proteins; Structural biology

Subject Areas: Biology and Bio-materials, Chemistry, Medicine


Instruments: I03-Macromolecular Crystallography , I04-1-Macromolecular Crystallography (fixed wavelength)

Other Facilities: ID30A-1 at ESRF

Added On: 09/11/2022 09:51

Documents:
s41598-022-23264-z.pdf

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Cancer Biochemistry Chemistry Structural biology Biophysics Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)