Publications by authors named "Dhanak D"

Article Synopsis
  • Mutations in a protein called calreticulin (mutCALR) cause blood disorders known as myeloproliferative neoplasms (MPNs), but there aren’t any treatments specifically targeting this mutation.
  • A new antibody called INCA033989 can specifically attack cells with the mutCALR mutation, stopping them from growing and causing problems.
  • In tests on mice, INCA033989 not only prevented issues like high blood cell counts but also showed it could help treat the disease without harming normal blood cell production.
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Background: Brief psychosocial intervention (BPI) is a treatment for adolescent depression that has recently demonstrated clinical effectiveness in a controlled trial. The aim of this study is to explore experiences of adolescents with major depression receiving BPI treatment in the context of good treatment outcomes.

Method: A subsample of five interviews from a larger study of adolescents' experiences of BPI was purposively selected, focusing on good-outcome cases.

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Recent characterization of broadly neutralizing antibodies (bnAbs) against influenza virus identified the conserved hemagglutinin (HA) stem as a target for development of universal vaccines and therapeutics. Although several stem bnAbs are being evaluated in clinical trials, antibodies are generally unsuited for oral delivery. Guided by structural knowledge of the interactions and mechanism of anti-stem bnAb CR6261, we selected and optimized small molecules that mimic the bnAb functionality.

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KRAS was recently identified to be potentially druggable by allele-specific covalent targeting of Cys-12 in vicinity to an inducible allosteric switch II pocket (S-IIP). Success of this approach requires active cycling of KRAS between its active-GTP and inactive-GDP conformations as accessibility of the S-IIP is restricted only to the GDP-bound state. This strategy proved feasible for inhibiting mutant KRAS in vitro; however, it is uncertain whether this approach would translate to in vivo.

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Advances in understanding the role and molecular mechanisms underlying immune surveillance and control of (pre)malignancies is revolutionizing clinical practice in the treatment of cancer. Presently, multiple biologic drugs targeting the immune checkpoint proteins PD(L)1 or CTLA4 have been approved and/or are in advanced stages of clinical development for many cancers. In addition, combination therapy with these agents and other immunomodulators is being intensively explored with the aim of improving primary response rates or prolonging overall survival.

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Chemical probes are powerful reagents with increasing impacts on biomedical research. However, probes of poor quality or that are used incorrectly generate misleading results. To help address these shortcomings, we will create a community-driven wiki resource to improve quality and convey current best practice.

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Epigenetic dysregulation has emerged as an important mechanism in cancer. Alterations in epigenetic machinery have become a major focus for targeted therapies. The current report describes the discovery and biological activity of a cyclopropylamine containing inhibitor of Lysine Demethylase 1 (LSD1), GSK2879552.

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The EZH2 methyltransferase silences gene expression through methylation of histone H3 on lysine 27 (H3K27). Recently, EZH2 mutations have been reported at Y641, A677, and A687 in non-Hodgkin lymphoma. Although the Y641F/N/S/H/C and A677G mutations exhibit clearly increased activity with substrates dimethylated at lysine 27 (H3K27me2), the A687V mutant has been shown to prefer a monomethylated lysine 27 (H3K27me1) with little gain of activity toward H3K27me2.

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Emerging evidence supports an important, etiologic role for epigenetic modifications in cancer. Various post translational modifications of histone proteins together with DNA methylation constitute an 'epigenetic code' regulating the transcriptional status of the cell and aberrant writing and/or interpretation of the code can contribute to a dysregulated, hyperproliferative state. In some cases, epigenetic deregulation has also been reported to result in tumor initiation.

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Deregulation of lysine methylation signalling has emerged as a common aetiological factor in cancer pathogenesis, with inhibitors of several histone lysine methyltransferases (KMTs) being developed as chemotherapeutics. The largely cytoplasmic KMT SMYD3 (SET and MYND domain containing protein 3) is overexpressed in numerous human tumours. However, the molecular mechanism by which SMYD3 regulates cancer pathways and its relationship to tumorigenesis in vivo are largely unknown.

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Human gene expression patterns are controlled and coordinated by the activity of a diverse array of epigenetic regulators, including histone methyltransferases, acetyltransferases, and chromatin remodelers. Deregulation of these epigenetic pathways can lead to genome-wide changes in gene expression, with serious disease consequences. In recent years, research has suggested that cross talk between genomic (i.

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EZH2/PRC2 catalyzes transcriptionally repressive methylation at lysine 27 of histone H3 and has been associated with numerous cancer types. Point mutations in EZH2 at Tyr641 and Ala677 identified in non-Hodgkin lymphomas alter substrate specificity and result in increased trimethylation at histone H3K27. Interestingly, EZH2/PRC2 is activated by binding H3K27me3 marks on histones, and this activation is proposed as a mechanism for self-propagation of gene silencing.

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A plethora of groundbreaking studies have demonstrated the importance of chromatin-associated proteins and post-translational modifications of histones, proteins and DNA (so-called epigenetic modifications) for transcriptional control and normal development. Disruption of epigenetic control is a frequent event in disease, and the first epigenetic-based therapies for cancer treatment have been approved. A generation of new classes of potent and specific inhibitors for several chromatin-associated proteins have shown promise in preclinical trials.

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BET family proteins are epigenetic regulators known to control expression of genes involved in cell growth and oncogenesis. Selective inhibitors of BET proteins exhibit potent anti-proliferative activity in a number of hematologic cancer models, in part through suppression of the MYC oncogene and downstream Myc-driven pathways. However, little is currently known about the activity of BET inhibitors in solid tumor models, and whether down-regulation of MYC family genes contributes to sensitivity.

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The histone H3-lysine 27 (H3K27) methyltransferase EZH2 plays a critical role in regulating gene expression, and its aberrant activity is linked to the onset and progression of cancer. As part of a drug discovery program targeting EZH2, we have identified highly potent, selective, SAM-competitive, and cell-active EZH2 inhibitors, including GSK926 (3) and GSK343 (6). These compounds are small molecule chemical tools that would be useful to further explore the biology of EZH2.

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In eukaryotes, post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2) and is involved in repressing gene expression through methylation of histone H3 on lysine 27 (H3K27). EZH2 overexpression is implicated in tumorigenesis and correlates with poor prognosis in several tumour types.

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The Aurora kinases play critical roles in the regulation of mitosis and are frequently overexpressed or amplified in human tumors. Selective inhibitors may provide a new therapy for the treatment of tumors with Aurora kinase amplification. Herein we describe our lead optimization efforts within a 7-azaindole-based series culminating in the identification of GSK1070916 (17k).

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Phosphoinositide 3-kinase α (PI3Kα) is a critical regulator of cell growth and transformation, and its signaling pathway is the most commonly mutated pathway in human cancers. The mammalian target of rapamycin (mTOR), a class IV PI3K protein kinase, is also a central regulator of cell growth, and mTOR inhibitors are believed to augment the antiproliferative efficacy of PI3K/AKT pathway inhibition. 2,4-Difluoro-N-{2-(methyloxy)-5-[4-(4-pyridazinyl)-6-quinolinyl]-3-pyridinyl}benzenesulfonamide (GSK2126458, 1) has been identified as a highly potent, orally bioavailable inhibitor of PI3Kα and mTOR with in vivo activity in both pharmacodynamic and tumor growth efficacy models.

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Inhibition of mitotic kinesins represents a novel approach for the discovery of a new generation of anti-mitotic cancer chemotherapeutics. We report here the discovery of the first potent and selective inhibitor of centromere-associated protein E (CENP-E) 3-chloro-N-{(1S)-2-[(N,N-dimethylglycyl)amino]-1-[(4-{8-[(1S)-1-hydroxyethyl]imidazo[1,2-a]pyridin-2-yl}phenyl)methyl]ethyl}-4-[(1-methylethyl)oxy]benzamide (GSK923295; 1), starting from a high-throughput screening hit, 3-chloro-4-isopropoxybenzoic acid 2. Compound 1 has demonstrated broad antitumor activity in vivo and is currently in human clinical trials.

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Centromere-associated protein-E (CENP-E) is a kinetochore-associated mitotic kinesin that is thought to function as the key receptor responsible for mitotic checkpoint signal transduction after interaction with spindle microtubules. We have identified GSK923295, an allosteric inhibitor of CENP-E kinesin motor ATPase activity, and mapped the inhibitor binding site to a region similar to that bound by loop-5 inhibitors of the kinesin KSP/Eg5. Unlike these KSP inhibitors, which block release of ADP and destabilize motor-microtubule interaction, GSK923295 inhibited release of inorganic phosphate and stabilized CENP-E motor domain interaction with microtubules.

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The protein kinases, Aurora A, B, and C have critical roles in the regulation of mitosis and are frequently overexpressed or amplified in human tumors. GSK1070916, is a novel ATP competitive inhibitor that is highly potent and selective for Aurora B/C kinases. Human tumor cells treated with GSK1070916 show dose-dependent inhibition of phosphorylation on serine 10 of Histone H3, a substrate specific for Aurora B kinase.

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The synthesis and optimisation of HCV NS5B polymerase inhibitors with improved potency versus the existing compound 1 is described. Substitution in the benzothiadiazine portion of the molecule, furnishing improvement in potency in the high protein Replicon assay, is highlighted, culminating in the discovery of 12h, a highly potent oxyacetamide derivative.

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