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Nathan West

Bio: Nathan West is an academic researcher from Harvard University. The author has contributed to research in topics: Histone deacetylase & Histone deacetylase 2. The author has an hindex of 12, co-authored 13 publications receiving 4937 citations. Previous affiliations of Nathan West include Colorado State University & Massachusetts Institute of Technology.

Papers
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Journal ArticleDOI
23 Dec 2010-Nature
TL;DR: A cell-permeable small molecule (JQ1) that binds competitively to acetyl-lysine recognition motifs, or bromodomains is reported, establishing proof-of-concept for targeting protein–protein interactions of epigenetic ‘readers’, and providing a versatile chemical scaffold for the development of chemical probes more broadly throughout the b romodomain family.
Abstract: Epigenetic proteins are intently pursued targets in ligand discovery. So far, successful efforts have been limited to chromatin modifying enzymes, or so-called epigenetic 'writers' and 'erasers'. Potent inhibitors of histone binding modules have not yet been described. Here we report a cell-permeable small molecule (JQ1) that binds competitively to acetyl-lysine recognition motifs, or bromodomains. High potency and specificity towards a subset of human bromodomains is explained by co-crystal structures with bromodomain and extra-terminal (BET) family member BRD4, revealing excellent shape complementarity with the acetyl-lysine binding cavity. Recurrent translocation of BRD4 is observed in a genetically-defined, incurable subtype of human squamous carcinoma. Competitive binding by JQ1 displaces the BRD4 fusion oncoprotein from chromatin, prompting squamous differentiation and specific antiproliferative effects in BRD4-dependent cell lines and patient-derived xenograft models. These data establish proof-of-concept for targeting protein-protein interactions of epigenetic 'readers', and provide a versatile chemical scaffold for the development of chemical probes more broadly throughout the bromodomain family.

3,489 citations

Journal ArticleDOI
TL;DR: The synthesis and study of a focused library of cinnamic hydroxamates allowed the identification of a first non-selective HDAC inhibitor, which will guide a more informed use of HDAC inhibitors as chemical probes and therapeutic agents.
Abstract: In contrast to perceived nonselectivity, biochemical profiling reveals that currently available HDAC inhibitors predominantly inhibit only class I and IIb HDAC enzymes. A new pan-selective inhibitor, obtained by screening a focused library, provides an important tool for studying class IIa HDACs.

682 citations

Journal ArticleDOI
TL;DR: It is demonstrated that CRLF2 is overexpressed in approximately 15% of adult and high-risk pediatric B-ALL that lack MLL, TCF3, TEL, and BCR/ABL rearrangements, but not in B-all with these rearrangement or other lymphoid malignancies.
Abstract: The prognosis for adults with precursor B-cell acute lymphoblastic leukemia (B-ALL) remains poor, in part from a lack of therapeutic targets. We identified the type I cytokine receptor subunit CRLF2 in a functional screen for B-ALL–derived mRNA transcripts that can substitute for IL3 signaling. We demonstrate that CRLF2 is overexpressed in approximately 15% of adult and high-risk pediatric B-ALL that lack MLL, TCF3, TEL, and BCR/ABL rearrangements, but not in B-ALL with these rearrangements or other lymphoid malignancies. CRLF2 overexpression can result from translocation with the IGH locus or intrachromosomal deletion and is associated with poor outcome. CRLF2 overexpressing B-ALLs share a transcriptional signature that significantly overlaps with a BCR/ABL signature, and is enriched for genes involved in cytokine receptor and JAK-STAT signaling. In a subset of cases, CRLF2 harbors a Phe232Cys gain-of-function mutation that promotes constitutive dimerization and cytokine independent growth. A mutually exclusive subset harbors activating mutations in JAK2. In fact, all 22 B-ALLs with mutant JAK2 that we analyzed overexpress CRLF2, distinguishing CRLF2 as the key scaffold for mutant JAK2 signaling in B-ALL. Expression of WT CRLF2 with mutant JAK2 also promotes cytokine independent growth that, unlike CRLF2 Phe232Cys or ligand-induced signaling by WT CRLF2, is accompanied by JAK2 phosphorylation. Finally, cells dependent on CRLF2 signaling are sensitive to small molecule inhibitors of either JAKs or protein kinase C family kinases. Together, these findings implicate CRLF2 as an important factor in B-ALL with diagnostic, prognostic, and therapeutic implications.

314 citations

Journal ArticleDOI
TL;DR: A unique bead-based strategy is developed for the identification of inducers of fetal hemoglobin transcripts in primary human erythroid cells and the potential of isoform-selective inhibitors of HDAC1 and HDAC2 for the treatment of sickle cell disease is suggested.
Abstract: The worldwide burden of sickle cell disease is enormous, with over 200,000 infants born with the disease each year in Africa alone. Induction of fetal hemoglobin is a validated strategy to improve symptoms and complications of this disease. The development of targeted therapies has been limited by the absence of discrete druggable targets. We developed a unique bead-based strategy for the identification of inducers of fetal hemoglobin transcripts in primary human erythroid cells. A small-molecule screen of bioactive compounds identified remarkable class-associated activity among histone deacetylase (HDAC) inhibitors. Using a chemical genetic strategy combining focused libraries of biased chemical probes and reverse genetics by RNA interference, we have identified HDAC1 and HDAC2 as molecular targets mediating fetal hemoglobin induction. Our findings suggest the potential of isoform-selective inhibitors of HDAC1 and HDAC2 for the treatment of sickle cell disease.

191 citations

Journal ArticleDOI
TL;DR: In this article, an HSP90 inhibitor, PU-H71, demonstrated efficacy in cell line and mouse models of the MPN polycythemia vera and essential thrombocytosis (ET) by disrupting JAK2 protein stability.
Abstract: JAK2 kinase inhibitors were developed for the treatment of myeloproliferative neoplasms (MPNs), following the discovery of activating JAK2 mutations in the majority of patients with MPN. However, to date JAK2 inhibitor treatment has shown limited efficacy and apparent toxicities in clinical trials. We report here that an HSP90 inhibitor, PU-H71, demonstrated efficacy in cell line and mouse models of the MPN polycythemia vera (PV) and essential thrombocytosis (ET) by disrupting JAK2 protein stability. JAK2 physically associated with both HSP90 and PU-H71 and was degraded by PU-H71 treatment in vitro and in vivo, demonstrating that JAK2 is an HSP90 chaperone client. PU-H71 treatment caused potent, dose-dependent inhibition of cell growth and signaling in JAK2 mutant cell lines and in primary MPN patient samples. PU-H71 treatment of mice resulted in JAK2 degradation, inhibition of JAK-STAT signaling, normalization of peripheral blood counts, and improved survival in MPN models at doses that did not degrade JAK2 in normal tissues or cause substantial toxicity. Importantly, PU-H71 treatment also reduced the mutant allele burden in mice. These data establish what we believe to be a novel therapeutic rationale for HSP90 inhibition in the treatment of JAK2-dependent MPN.

180 citations


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Journal ArticleDOI
06 Jul 2012-Cell
TL;DR: The basic principles behind DNA methylation, histone modification, nucleosome remodeling, and RNA-mediated targeting are presented and the evidence suggesting that their misregulation can culminate in cancer is highlighted.

2,501 citations

Journal ArticleDOI
TL;DR: Next-generation sequencing is providing a window for visualizing the human epigenome and how it is altered in cancer, including linking epigenetic abnormalities to mutations in genes that control DNA methylation, the packaging and the function of DNA in chromatin, and metabolism.
Abstract: The past decade has highlighted the central role of epigenetic processes in cancer causation, progression and treatment. Next-generation sequencing is providing a window for visualizing the human epigenome and how it is altered in cancer. This view provides many surprises, including linking epigenetic abnormalities to mutations in genes that control DNA methylation, the packaging and the function of DNA in chromatin, and metabolism. Epigenetic alterations are leading candidates for the development of specific markers for cancer detection, diagnosis and prognosis. The enzymatic processes that control the epigenome present new opportunities for deriving therapeutic strategies designed to reverse transcriptional abnormalities that are inherent to the cancer epigenome.

2,483 citations

Journal ArticleDOI
11 Apr 2013-Cell
TL;DR: This work investigates how inhibition of the widely expressed transcriptional coactivator BRD4 leads to selective inhibition ofThe MYC oncogene in multiple myeloma (MM), and finds that super-enhancers were found at key oncogenic drivers in many other tumor cells.

2,292 citations