Project description:Transcription factors are among the most attractive therapeutic targets but are considered largely undruggable. Here we provide evidence that small molecule-mediated partitioning of the androgen receptor, an oncogenic transcription factor, into phase-separated condensates has therapeutic effect in prostate cancer. We show that the phase separation capacity of the androgen receptor is driven by aromatic residues and short unstable helices in its intrinsically disordered activation domain. Based on this knowledge, we developed tool compounds that covalently attach aromatic moieties to cysteines in the receptors’ activation domain. The compounds enhanced partitioning of the receptor into condensates, facilitated degradation of the receptor, inhibited androgen receptor-dependent transcriptional programs, and had antitumorigenic effect in mouse models of prostate cancer and castration resistant prostate cancer. These results establish a generalizable framework to target the phase-separation capacity of intrinsically disordered regions in oncogenic transcription factors and other disease-associated proteins with therapeutic intent.
Project description:Transcription factors are among the most attractive therapeutic targets but are considered largely 'undruggable' in part due to the intrinsically disordered nature of their activation domains. Here we show that the aromatic character of the activation domain of the androgen receptor, a therapeutic target for castration-resistant prostate cancer, is key for its activity as transcription factor, allowing it to translocate to the nucleus and partition into transcriptional condensates upon activation by androgens. On the basis of our understanding of the interactions stabilizing such condensates and of the structure that the domain adopts upon condensation, we optimized the structure of a small-molecule inhibitor previously identified by phenotypic screening. The optimized compounds had more affinity for their target, inhibited androgen-receptor-dependent transcriptional programs, and had an antitumorigenic effect in models of castration-resistant prostate cancer in cells and in vivo. These results suggest that it is possible to rationally optimize, and potentially even to design, small molecules that target the activation domains of oncogenic transcription factors.
Project description:Starting from the structure of the human ASF1-histone complex, we developed a rational design strategy combining epitope tethering and optimization of interface contacts to identify a potent peptide inhibitor with a dissociation constant of 3 nM. LC-MS/MS was used to identify in vivo targets of the most prominent peptide inhibitor.
Project description:High throughput screening and subsequent hit validation identified 4-isopropyl-3-(2-((1-phenylethyl) amino)pyrimidin-4-yl)oxazolidin-2-one as a potent inhibitor of IDH1R132H. Synthesis of the 4 separate diastereomers identified the (S,S)-diastereomer (IDH125) as the most potent isomer. This also showed reasonable cellular activity and excellent selectivity vs IDH1wt. Initial SAR exploration identified the key tolerances and potential for optimization. X-ray crystallography identified a functionally relevant allosteric binding site amenable to inhibitors which can penetrate the blood-brain barrier, and aided rational optimization. Potency improvement and modulation of the physico-chemical properties identified (S)-3-(2-(((S)-1-(5-(4-fluoro-3-methylphenyl)pyrimidin-2-yl)ethyl)amino)pyrimidin-4-yl)-4-isopropyloxazolidin-2-one (IDH889) with good in-vivo exposure and in-vivo activity in a mutant IDH1 xenograft mouse model. identified the (S,S)-diastereomer (IDH125) as the most potent isomer. This also showed reasonable cellular activity and excellent selectivity vs IDH1wt. Initial SAR exploration identified the key tolerances and potential for optimization. X-ray crystallography identified a functionally relevant allosteric binding site amenable to inhibitors which can penetrate the blood-brain barrier, and aided rational optimization. Potency improvement and modulation of the physico-chemical properties identified (S)-3-(2-(((S)-1-(5-(4-fluoro-3-methylphenyl)pyrimidin-2-yl)ethyl)amino)pyrimidin-4-yl)-4-isopropyloxazolidin-2-one (IDH889) with good in-vivo exposure and in-vivo activity in a mutant IDH1 xenograft mouse model
Project description:T-3775440 is an irreversible inhibitor of the chromatin demethylase LSD1. Here we describe the anti-cancer effects and mechanism of action of T-3775440 in small cell lung cancer (SCLC). T-3775440 inhibited proliferation of SCLC cells in vitro and retarded SCLC tumor growth in vivo. Our results argue that LSD1 plays an important role in neuroendocrine-associated transcription and cell proliferation of SCLC via interactions with the SNAG domain proteins INSM1 and GFI1B. Targeting these critical interactions with LSD1 inhibitors offers a novel rational strategy to therapeutically manage SCLC.