c-Abl kinase activity is regulated by a unique mechanism involving the formation of an autoinhibited conformation in which the N-terminal myristoyl group binds intramolecularly to the myristoyl binding site on the kinase domain and induces the bending of the αI helix that creates a docking surface for the SH2 domain. Here, we report a small-molecule c-Abl activator, DPH, that displays potent enzymatic and cellular activity in stimulating c-Abl activation. Structural analyses indicate that DPH binds to the myristoyl binding site and prevents the formation of the bent conformation of the αI helix through steric hindrance, a mode of action distinct from the previously identified allosteric c-Abl inhibitor, GNF-2, that also binds to the myristoyl binding site.
View Article and Find Full Text PDFThe PI3K signaling pathway is activated in a broad spectrum of human cancers, either directly by genetic mutation or indirectly via activation of receptor tyrosine kinases or inactivation of the PTEN tumor suppressor. The key nodes of this pathway have emerged as important therapeutic targets for the treatment of cancer. In this study, we show that (-)-epigallocatechin-3-gallate (EGCG), a major component of green tea, is an ATP-competitive inhibitor of both phosphoinositide-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) with K(i) values of 380 and 320nM respectively.
View Article and Find Full Text PDFBackground: Despite the rapid rise in the use of multicompartmental compliance aids (MCAs), little is known about the role they play in self-management of medication.
Aim: To explore the perceived benefits of MCAs for people using them to manage their own or a relative's medication.
Design Of Study: Qualitative study using in-depth interviews.
The synthesis of five 2-arylnaphtho[2,3-d]oxazole-4,9-dione derivatives was accomplished by refluxing 2-amino-3-bromo-1,4-naphthoquinone with appropriate benzoyl chloride analogs at elevated temperatures. In vitro anticancer evaluation of these compounds was performed on androgen-dependent, LNCaP, and androgen-independent, PC3, human prostate cancer cell lines. In general, these compounds displayed slightly stronger cytotoxicity on the androgen-dependent LNCaP than on the androgen-independent PC3 prostate cancer cell lines.
View Article and Find Full Text PDFObjectives: Peripheral arterial disease (PAD) is a common and often overlooked entity responsible for considerable morbidity and mortality. Recent evidence suggests that nontraditional risk factors such as vitamin D may contribute to atherosclerosis. We hypothesized that vitamin D status was associated with cardiovascular risk factors and that vitamin D deficiency (25(OH)D <20 ng/mL) enhanced the risk of amputation.
View Article and Find Full Text PDFCells run on carbohydrates. Glycans, sequences of carbohydrates conjugated to proteins and lipids, are arguably the most abundant and structurally diverse class of molecules in nature. Recent advances in glycomics reveal the scope and scale of their functional roles and their impact on human disease.
View Article and Find Full Text PDFEZH2, the catalytic subunit of the PRC2 complex, catalyzes the mono- through trimethylation of lysine 27 on histone H3 (H3K27). Histone H3K27 trimethylation is a mechanism for suppressing transcription of specific genes that are proximal to the site of histone modification. Point mutations of the EZH2 gene (Tyr641) have been reported to be linked to subsets of human B-cell lymphoma.
View Article and Find Full Text PDFEpigenetic control of gene transcription is the result of enzyme-mediated covalent modifications of promoter-region DNA sites and of histone proteins around which chromosomal DNA is wound. Many of the enzymes that mediate these epigenetic reactions are dysregulated in human diseases. Small molecule inhibitors against two classes of these enzymes have been approved for use in patients: DNA methyltransferase (DNMT) inhibitors and histone deacetylase inhibitors.
View Article and Find Full Text PDFPeripheral arterial disease is a common and often overlooked entity responsible for considerable morbidity and mortality. Recent evidence suggests that nontraditional risk factors such as vitamin D deficiency may contribute to atherosclerosis and increased cardiovascular morbidity and mortality, hence monitoring of vitamin D status is essential. This review tries to examine this entity.
View Article and Find Full Text PDFO-linked β-N-acetylglucosamine (O-GlcNAc) is a sugar attachment to serine or threonine hydroxyl moieties on nuclear and cytoplasmic proteins. In many ways, O-GlcNAcylation is similar to phosphorylation because both post-translational modifications cycle rapidly in response to internal or environmental cues. O-GlcNAcylated proteins are involved in transcription, translation, cytoskeletal assembly, signal transduction, and many other cellular functions.
View Article and Find Full Text PDFThe 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).
View Article and Find Full Text PDFInhibition 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.
View Article and Find Full Text PDFBackground Aims: The aim was to evaluate cartilage regeneration in animal models involving induced knee joint damage. Through cell-mediated gene therapy methods, a cell mixture comprising a 3:1 ratio of genetically unmodified human chondrocytes and transforming growth factor beta-1 (TGF-beta1)-secreting human chondrocytes (TG-C), generated via retroviral transduction, resulted in successful cartilage proliferation in damaged regions.
Methods: Non-clinical toxicology assessments for efficacy, biodistribution and local/systemic toxicity of single intra-articular administration of the cell mixture in mice, rabbits and goats was conducted.
Expert Opin Drug Discov
April 2010
The extent and duration of pharmacological action is determined by the lifetime of drug occupancy on a molecular target. This lifetime is defined by dynamic processes that control the rates of drug association and dissociation from the target. Recently, the term residence time has been coined to describe experimental measurements that can be related to the lifetime of the binary drug-target complex, and this in turn to durable, pharmacodynamic activity.
View Article and Find Full Text PDFBackground: Worldwide among men, prostate cancer ranks third in cancer occurrence and sixth in cancer mortality. A number of 1, 4-naphthoquinone derivatives have been identified that possess significant pharmacological effects associated with antitumor activities. In this study, the in vitro effects of N-(3-chloro-1,4-dioxo 1,4-dihydro-naphthalen-2-yl)-benzamide (NCDDNB) were evaluated on androgen-dependent (CWR-22) and androgen-independent (PC-3, DU-145) human prostate cancer cell lines, and on a normal bone marrow cell line (HS-5).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2010
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.
View Article and Find Full Text PDFJ Am Med Dir Assoc
February 2010
Objective: The present study was undertaken to determine if a seasonal bias was present for vitamin D testing among Northeast Tennessee veterans, in whom vitamin D deficiency is common.
Design: Medical chart review.
Setting: VA Medical Center.
Clostridium difficile and staphylococcal infections are associated with increased morbidity, mortality and healthcare costs. Vitamin D deficiency may also contribute to increased healthcare costs. There is increasing evidence that vitamin D may have an antimicrobial role.
View Article and Find Full Text PDFBackground: Systematic reviews have identified a range of brief interventions which increase physical activity in previously sedentary people. There is an absence of evidence about whether follow up beyond three months can maintain long term physical activity. This study assesses whether it is worth providing motivational interviews, three months after giving initial advice, to those who have become more active.
View Article and Find Full Text PDFThe protein methyltransferases (PMTs) - which methylate protein lysine and arginine residues and have crucial roles in gene transcription - are emerging as an important group of enzymes that play key parts in normal physiology and human diseases. The collection of human PMTs is a large and diverse group of enzymes that have a common mechanism of catalysis. Here, we review the biological, biochemical and structural data that together present PMTs as a novel, chemically tractable target class for drug discovery.
View Article and Find Full Text PDFAmong the insects reported by Copeland (1989) breeding in the waters retained by treeholes in Indiana was a scuttle fly identified by W. H. Robinson as Megaselia scalaris (Loew).
View Article and Find Full Text PDFBackground: Breast cancer is the most frequent cancer and the second leading cause of cancer deaths in women today. A number of 1,4-naphthoquinone derivatives have been found to possess significant pharmacological effects associated with marked antimicrobial and antitumor activities. In the present study, the in vitro effect of 2,3-dichloro-5,8-dimethoxy-1,4-naphthoquinone (DCDMNQ) was evaluated on estrogen-positive MCF-7 and estrogen-negative MDA-MB-436 and Hs-578T human breast cancer cell lines.
View Article and Find Full Text PDFThe Smoothened receptor (Smo) mediates hedgehog (Hh) signaling critical for development, cell growth, and migration, as well as stem cell maintenance. Aberrant Hh signaling pathway activation has been implicated in a variety of cancers, and small-molecule antagonists of Smo have entered human clinical trials for the treatment of cancer. Here, we report the biochemical characterization of allosteric interactions of agonists and antagonists for Smo.
View Article and Find Full Text PDFThe Aurora kinases AurA, B and C are serine/threonine protein kinases that play essential roles in mitosis and cytokinesis. Among them, AurB is required for maintaining proper chromosome alignment, separation and segregation during mitosis, and regulating a number of critical processes involved in cytokinesis. AurB overexpression has been observed in a variety of cancer cell lines, and inhibition of AurB has been shown to induce tumour regression in mouse xenograft models.
View Article and Find Full Text PDFHigh-throughput screening (HTS) is a common mechanism for identifying lead compounds for drug discovery efforts. Small molecules can inhibit enzymes by a variety of mechanisms, such as competitive, noncompetitive, and uncompetitive with respect to the substrate(s) of the catalytic reaction. To optimize the chances of finding the broadest diversity of inhibitor modalities during screening, one must run assays under ;;balanced'' conditions where the potency of inhibitors with various modes of action falls within a similar range.
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