SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin subfamily A member 2 (SMARCA2), also known as Brahma homologue (BRM), is a Snf2-family DNA-dependent ATPase. BRM and its ...close homologue Brahma-related gene 1 (BRG1), also known as SMARCA4, are mutually exclusive ATPases of the large ATP-dependent SWI/SNF chromatin-remodeling complexes involved in transcriptional regulation of gene expression. No small molecules have been reported that modulate SWI/SNF chromatin-remodeling activity via inhibition of its ATPase activity, an important goal given the well-established dependence of BRG1-deficient cancers on BRM. Here, we describe allosteric dual BRM and BRG1 inhibitors that downregulate BRM-dependent gene expression and show antiproliferative activity in a BRG1-mutant-lung-tumor xenograft model upon oral administration. These compounds represent useful tools for understanding the functions of BRM in BRG1-loss-of-function settings and should enable probing the role of SWI/SNF functions more broadly in different cancer contexts and those of other diseases.
SHP2 is a nonreceptor protein tyrosine phosphatase within the mitogen-activated protein kinase (MAPK) pathway controlling cell growth, differentiation, and oncogenic transformation. SHP2 also ...participates in the programed cell death pathway (PD-1/PD-L1) governing immune surveillance. Small-molecule inhibition of SHP2 has been widely investigated, including in our previous reports describing SHP099 (2), which binds to a tunnel-like allosteric binding site. To broaden our approach to allosteric inhibition of SHP2, we conducted additional hit finding, evaluation, and structure-based scaffold morphing. These studies, reported here in the first of two papers, led to the identification of multiple 5,6-fused bicyclic scaffolds that bind to the same allosteric tunnel as 2. We demonstrate the structural diversity permitted by the tunnel pharmacophore and culminated in the identification of pyrazolopyrimidinones (e.g., SHP389, 1) that modulate MAPK signaling in vivo. These studies also served as the basis for further scaffold morphing and optimization, detailed in the following manuscript.
Abstract
Uveal melanoma is a rare and aggressive cancer that originates in the eye. Currently, there are no approved targeted therapies and very few effective treatments for this cancer. Although ...activating mutations in the G protein alpha subunits, GNAQ and GNA11, are key genetic drivers of the disease, few additional drug targets have been identified. Recently, studies have identified context-specific roles for the mammalian SWI/SNF chromatin remodeling complexes (also known as BAF/PBAF) in various cancer lineages. Here, we find evidence that the SWI/SNF complex is essential through analysis of functional genomics screens and further validation in a panel of uveal melanoma cell lines using both genetic tools and small-molecule inhibitors of SWI/SNF. In addition, we describe a functional relationship between the SWI/SNF complex and the melanocyte lineage–specific transcription factor Microphthalmia-associated Transcription Factor, suggesting that these two factors cooperate to drive a transcriptional program essential for uveal melanoma cell survival. These studies highlight a critical role for SWI/SNF in uveal melanoma, and demonstrate a novel path toward the treatment of this cancer.
Abstract
Protein tyrosine phosphatase SHP2 is an oncoprotein associated with cancer as well as a potential immune modulator due to its role in the programmed cell death PD-L1/PD-1 pathway. Small ...molecule inhibition of SHP2 has been widely investigated including our previous reports describing SHP099, which binds to a tunnel-like allosteric binding site. To broaden our approach to allosteric inhibition of SHP2, we conducted additional hit finding, evaluation, and structure-based scaffold morphing. These studies led to the identification of multiple, potent inhibitor chemotypes, an additional and distinct allosteric binding site, and the identification of SHP394, an orally efficacious inhibitor of SHP2 with improved potency and enhanced pharmacokinetic properties. Overall, this work improves upon our previously described allosteric inhibitors, and exemplifies and extends the range of permissible chemical templates that inhibit SHP2 via the allosteric mechanism.
Citation Format: Matthew J. LaMarche, Jeff Bagdanoff, Mike Acker, Ying-Nan Chen, Homan Chan, Michael Dore, Brant Firestone, Michelle Fodor, Jorge Garcia-Fortanet, Murphy Hentemann, Mitsunori Kato, Robert Koenig, Laura La Bonte, Shumei Liu, Movarid Mohseni, Rukundo Ntaganda, Patrick Sarver, Troy Smith, Martin Sendzik, Travis Stams, Stan Spence, Chris Towler, Hongyun Wang, Ping Wang, Sarah Williams, Zhouliang Chen, Huaixiang Hao, Gang Liu, Chen Liu, Eric McNeill, Bing Yu. Allosteric SHP2 phosphatase inhibition: Multiple mechanisms and chemotypes abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-005.
N-acyl-alpha-amino amides were prepared, without the necessity of chromatographic purification, in a single step by heating the corresponding alpha-keto ester in methanolic ammonia.
The first chapter of the thesis covers a simple one-step methodology to synthesize N-acyl-α-amino amides directly from α-keto esters and ammonia. The factors that govern this reaction have been ...studied, and the mechanism through which it proceeds has been briefly investigated. The substrate scope of the methodology was found to be broad, and a wide range of N-acyl α-amino amides were synthesized in good to excellent isolated yields. In all cases the desired products were isolated in high purity by crystallization, and did not require further chromatographic purification. The X-ray crystal structures of three N-acyl α-amino amides were also obtained. In addition, the acid hydrolysis of these derivatives was shown to furnish the corresponding unnatural α-amino acids in high yields after purification by ion exchange chromatography. The second chapter of the thesis describes our progress towards the synthesis of chiral acyclic diaminocarbenes (ADC), and their ultimate application as ligands in enantioselective catalysis. Towards this end, we have synthesized six chiral formamidinium salts, as precursors to chiral ADC with either C 2- or C1-symmetry, in good to excellent yields. An X-ray crystal structure of a C2-symmetric formamidinium iodide salt was obtained. In addition, the attempted formation of a chiral ADC-metal complex from the corresponding formamidinium salt, via deprotonation with LDA and reaction with the metal salt, instead resulted in the isolation of the corresponding urea. The structure of the urea was proven by X-ray crystallography, and its formation was assumed to arise from the oxidation of the free chiral ADC with adventitious oxygen.
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