Histone phosphorylation-dependent screening platform for identification of inhibitors to treat neuroblastoma

Project Summary In this proposal we will develop a synthetic nucleosome based drug screening platform to identify novel therapeutics to treat neuroblastoma Histone acetylation is associated with gene activation and is catalyzed by histone acetyltransferase enzymes HATs Histone hyperacetylation is a key driver of neuroblastoma Several recent studies demonstrate that inhibition of HAT activity dramatically slows cancer progression in vivo However there are no FDA approved HAT inhibitors for human use New HAT inhibitors therefore are greatly needed to develop therapies for hyperacetylation based diseases such as neuroblastoma Nucleosomes composed of the core histone proteins and DNA are the fundamental repeating units of chromatin Chromatin structure and function are altered upon the addition or removal of histone post translational modifications PTMs such as methylation acetylation and phosphorylation by histone modifying enzymes The histone code hypothesis stipulates that nucleosomal PTMs function in interdependent networks to regulate downstream gene expression Current histone modifying assays typically use modified histone proteins fragments as substrates which poorly mimic native chromatin architecture By contrast synthetic nucleosomes carrying specific PTMs termed designer nucleosomes or dNucs provide a superior substrate for the study of histone modifying enzymes by better replicating chromatin structure EpiCypher is a world leader in recombinant nucleosome synthesis and is pioneering the development of dNuc based technologies for drug discovery applications Phosphorylation of histone H at serine H S ph is strongly associated with gene activation and acts as an epigenetic signaling hub that significantly enhances the activity of multiple HATs In this Phase I proposal we will leverage this unique feature of the histone code to develop an innovative screening platform to identify HAT inhibitors We hypothesize that screening HAT enzymes in the presence of H S ph will recapitulate in vivo activity and reveal context dependent inhibitors providing a robust and powerful assay platform for drug discovery We will develop for the first time methods to synthesize high quality H S ph modified nucleosomes at commercial grade and scale We will then use these dNucs as biochemical substrates to establish HAT activity assays using H S ph dependent enzymes Finally we will demonstrate feasibility that this assay platform can be used for drug discovery by examining phosphorylation context dependent HAT activity following treatment of H S ph modified nucleosomes with tool HAT inhibitors In Phase II we will further optimize commercialization of H S ph modified nucleosomes to support high throughput assay development We will also develop additional H S ph dependent HAT activity inhibitor assays which we will market as stand alone inhibitor kits to both industrial and academic research customers The innovative drug discovery platform described herein will accelerate the identification HAT inhibitors to treat devastating human diseases such as neuroblastoma Project Narrative Neuroblastoma is the most common cancer to be diagnosed before the age of one and affects more than million children in the United States alone Recent studies demonstrate that inhibition of histone acetyltransferases HATs significantly slows cancer proliferation and promotes cancer cell death however to date there are no FDA approved HAT inhibitors to treat this devastating disease In this proposal EpiCypher will develop an innovative drug discovery platform that leverages the power of in vivo chromatin interactions to accelerate the identification of new inhibitors that target HAT regulation