Evaluation of a new series of BET bromodomain inhibitors

Purpose and goal

This collaboration project aims to generate tool compounds selective to inhibit BD1 and BD2 in BET proteins that will be developed into clinical candidates. At this stage of the project the objective was to characterize a novel range of BETi using cell based assays to determine how they perform biologically as BETi. This was done while working both in the University research laboratory, and at RGD. Until Vinnova funding, the only characterisation of these compounds performed was done using in vitro binding analysis.

Expected results and effects

Using cell based assays I was able to demonstrate which of the current selection of tool compounds exert BETi effects in our cell system. The findings show us which compounds cause characteristic of BETi changes in the transcriptome, and whether or not they can cause cell arrest or death. Furthermore, we now have data that can show us how each compound may affect chromatin binding of individual BRD proteins. Using data generated in this project it is now possible to generate the next phase of BETi.

Planned approach and implementation

Characterisation of compounds was carried out in transgenic Myc-driven B lymphoma cell lines derived from mice. Cell viability and effects on cell cycle were studied using Cell Titer Glow and FACS analysis. Confirmation that cell cycle phenotypes were due to BET inhibition was done by qRT-PCR on a previously published gene set. Finally, a selection of candidates were tested for their ability to inhibit individual BRD proteins binding to chromatin.