1
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Tran U, Billingsley KL. Biological evaluation of indolactams for in vitro bryostatin 1-like activity. Bioorg Med Chem Lett 2024; 97:129570. [PMID: 38036273 DOI: 10.1016/j.bmcl.2023.129570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/01/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023]
Abstract
Small molecule activators of protein kinase C (PKC) have traditionally been classified as either tumor promoters or suppressors. Although bryostatin 1 has well established anti-cancer activity, most natural products that target the PKC regulator domain exhibit tumor promotion properties. In this study, we examine a focused library of indolactam analogues in cell-based assays to establish the structural features of the scaffold that enhance bryostatin 1-like activity. These systematic biological assessments identified specific indole substitution patterns that impart diminished tumor promotion behavior in vitro for indolactam analogues, while still maintaining nanomolar potency for PKC.
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Affiliation(s)
- UyenPhuong Tran
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, CA 92831, USA
| | - Kelvin L Billingsley
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL 60660, USA.
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2
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Targeting PKC in microglia to promote remyelination and repair in the CNS. Curr Opin Pharmacol 2021; 62:103-108. [PMID: 34965482 DOI: 10.1016/j.coph.2021.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/19/2021] [Indexed: 01/28/2023]
Abstract
Microglia and CNS-infiltrating macrophages play significant roles in the pathogenesis of neuroinflammatory and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Prolonged and dysregulated inflammatory responses by these innate immune cells can have deleterious effects on the surrounding CNS microenvironment, which can worsen neurodegeneration and demyelination. However, although chronic activation of pro-inflammatory microglia is maladaptive, other functional microglial subtypes play beneficial roles during CNS repair and regeneration. Therefore, there is a tremendous interest in understanding the underlying mechanism of the activation of these reparative/regenerative microglia. In this review, we focus on the potential role of PKC, a downstream signaling molecule of TREM2 and PLCγ2, and PKC modulators in promoting the activation of reparative/regenerative microglial subtypes as a novel therapy for neuroinflammatory and neurodegenerative diseases.
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3
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Araki Y, Hanaki Y, Kita M, Hayakawa K, Irie K, Nokura Y, Nakazaki A, Nishikawa T. Total synthesis and biological evaluation of oscillatoxins D, E, and F. Biosci Biotechnol Biochem 2021; 85:1371-1382. [PMID: 33851985 DOI: 10.1093/bbb/zbab042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/07/2021] [Indexed: 11/14/2022]
Abstract
Oscillatoxins (OTXs) and aplysiatoxins are biosynthetically related polyketides produced by marine cyanobacteria. We previously developed a synthetic route to phenolic O-methyl analogs of OTX-D and 30-methyl-OTX-D during collective synthesis of these natural products. According to our synthetic strategy, we achieved total synthesis of OTX-D, 30-methyl-OTX-D, OTX-E, and OTX-F by deprotecting the O-methyl group in an earlier intermediate, and determined their biological activities. Although OTX-D and 30-methyl-OTX-D have been reported to show antileukemic activity against L1210 cell line, we found that their cytotoxicity in vitro against this cell line is relatively weak (IC50: 29-52 µm). In contrast, OTX-F demonstrated cell line-selective antiproliferative activity against DMS-114 lung cancer cells, which implies that OTXs target as yet unknown target molecules as part of this unique activity.
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Affiliation(s)
- Yusuke Araki
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yusuke Hanaki
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Masaki Kita
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | | | - Kazuhiro Irie
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yoshihiko Nokura
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Atsuo Nakazaki
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Toshio Nishikawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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4
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Speidel JT, Affandi T, Jones DNM, Ferrara SE, Reyland ME. Functional proteomic analysis reveals roles for PKCδ in regulation of cell survival and cell death: Implications for cancer pathogenesis and therapy. Adv Biol Regul 2020; 78:100757. [PMID: 33045516 PMCID: PMC8294469 DOI: 10.1016/j.jbior.2020.100757] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/18/2022]
Abstract
Protein Kinase C-δ (PKCδ), regulates a broad group of biological functions and disease processes, including well-defined roles in immune function, cell survival and apoptosis. PKCδ primarily regulates apoptosis in normal tissues and non-transformed cells, and genetic disruption of the PRKCD gene in mice is protective in many diseases and tissue damage models. However pro-survival/pro-proliferative functions have also been described in some transformed cells and in mouse models of cancer. Recent evidence suggests that the contribution of PKCδ to specific cancers may depend in part on the oncogenic context of the tumor, consistent with its paradoxical role in cell survival and cell death. Here we will discuss what is currently known about biological functions of PKCδ and potential paradigms for PKCδ function in cancer. To further understand mechanisms of regulation by PKCδ, and to gain insight into the plasticity of PKCδ signaling, we have used functional proteomics to identify pathways that are dependent on PKCδ. Understanding how these distinct functions of PKCδ are regulated will be critical for the logical design of therapeutics to target this pathway.
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Affiliation(s)
- Jordan T Speidel
- Department of Craniofacial Biology, School of Dental Medicine, USA
| | - Trisiani Affandi
- Department of Craniofacial Biology, School of Dental Medicine, USA
| | | | - Sarah E Ferrara
- University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, USA.
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5
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Tran U, Zhang GC, Eom R, Billingsley KL, Ondrus AE. Small Molecule Intervention in a Protein Kinase C-Gli Transcription Factor Axis. ACS Chem Biol 2020; 15:1321-1327. [PMID: 32479053 DOI: 10.1021/acschembio.0c00355] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Aberrations in the Hedgehog (Hh) signaling pathway are responsible for a broad range of human cancers, yet only a subset rely on the activity of the clinical target, Smoothened (Smo). Emerging cases of cancers that are insensitive to Smo-targeting drugs demand new therapeutic targets and agents for inhibition. As such, we sought to pursue a recently discovered connection between the Hedgehog pathway transcription factors, the glioma-associated oncogene homologues (Glis), and protein kinase C (PKC) isozymes. Here, we report our assessment of a structurally diverse library of PKC effectors for their influence on Gli function. Using cell lines that employ distinct mechanisms of Gli activation up- and downstream of Smo, we identify a PKC effector that acts as a nanomolar Gli antagonist downstream of Smo through a mitogen-activated protein kinase kinase (MEK)-independent mechanism. This agent provides a unique tool to illuminate crosstalk between PKC isozymes and Hh signaling and new opportunities for therapeutic intervention in Hh pathway-dependent cancers.
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Affiliation(s)
- UyenPhuong Tran
- Department of Chemistry and Biochemistry, California State University Fullerton, 800 N State College Blvd, Fullerton, California 92831, United States
| | - Grace C. Zhang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, California 91125, United States
| | - Ryan Eom
- Department of Chemistry and Chemical Biology, Cornell University, 259 East Ave, Ithaca, New York 14853, United States
| | - Kelvin L. Billingsley
- Department of Chemistry and Biochemistry, California State University Fullerton, 800 N State College Blvd, Fullerton, California 92831, United States
| | - Alison E. Ondrus
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, California 91125, United States
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6
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Adelakun TA, Ding X, Ombati RM, Zhao ND, Obodozie-Ofoegbu OO, Di YT, Zhang Y, Hao XJ. A new highly oxygenated abietane diterpenoid and a new lysosome generating phorbol ester from the roots of Euphorbia fischeriana Steud. Nat Prod Res 2019; 34:3027-3035. [PMID: 31084207 DOI: 10.1080/14786419.2019.1607331] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Tiwalade A. Adelakun
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
- Medicinal Chemistry and Quality Control Department, National Institute of Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria
| | - Xiao Ding
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany Chinese Academy of Sciences, Kunming, China
| | - Rose M. Ombati
- University of Chinese Academy of Sciences, Beijing, China
| | - Ning-Dong Zhao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany Chinese Academy of Sciences, Kunming, China
| | - Obiageri O. Obodozie-Ofoegbu
- Medicinal Chemistry and Quality Control Department, National Institute of Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria
| | - Ying-Tong Di
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany Chinese Academy of Sciences, Kunming, China
| | - Yu Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany Chinese Academy of Sciences, Kunming, China
| | - Xiao-Jiang Hao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany Chinese Academy of Sciences, Kunming, China
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7
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Cummins TJ, Kedei N, Czikora A, Lewin NE, Kirk S, Petersen ME, McGowan KM, Chen JQ, Luo X, Johnson RC, Ravichandran S, Blumberg PM, Keck GE. Synthesis and Biological Evaluation of Fluorescent Bryostatin Analogues. Chembiochem 2018; 19:877-889. [PMID: 29424951 DOI: 10.1002/cbic.201700655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Indexed: 11/10/2022]
Abstract
To investigate the cellular distribution of tumor-promoting vs. non-tumor-promoting bryostatin analogues, we synthesized fluorescently labeled variants of two bryostatin derivatives that have previously shown either phorbol ester-like or bryostatin-like biological activity in U937 leukemia cells. These new fluorescent analogues both displayed high affinity for protein kinase C (PKC) binding and retained the basic properties of the parent unlabeled compounds in U937 assays. The fluorescent compounds showed similar patterns of intracellular distribution in cells, however; this argues against an existing hypothesis that various patterns of intracellular distribution are responsible for differences in biological activity. Upon further characterization, the fluorescent compounds revealed a slow rate of cellular uptake; correspondingly, they showed reduced activity for cellular responses that were only transient upon treatment with phorbol ester or bryostatin 1.
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Affiliation(s)
- Thomas J Cummins
- University of Utah, Department of Chemistry, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Room 4048, Bethesda, MD, 20892, USA
| | - Agnes Czikora
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Room 4048, Bethesda, MD, 20892, USA
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Room 4048, Bethesda, MD, 20892, USA
| | - Sharon Kirk
- University of Utah, Department of Chemistry, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
| | - Mark E Petersen
- University of Utah, Department of Chemistry, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
| | - Kevin M McGowan
- University of Utah, Department of Chemistry, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
| | - Jin-Qiu Chen
- Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Room 1044, Bethesda, MD, 20892, USA
| | - Xiaoling Luo
- Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Room 1044, Bethesda, MD, 20892, USA
| | - Randall C Johnson
- Advanced Biomedical and Computational Sciences Biomedical Informatics, and Data Science (BIDS), Directorate Frederick National Laboratory for Cancer Research (FNLCR), Leidos Biomedical Research, Inc., Building 430, Miller Drive, Fort Detrick, Frederick, MD, 21702, USA
| | - Sarangan Ravichandran
- Advanced Biomedical and Computational Sciences Biomedical Informatics, and Data Science (BIDS), Directorate Frederick National Laboratory for Cancer Research (FNLCR), Leidos Biomedical Research, Inc., Building 430, Miller Drive, Fort Detrick, Frederick, MD, 21702, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Room 4048, Bethesda, MD, 20892, USA
| | - Gary E Keck
- University of Utah, Department of Chemistry, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
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8
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Molecular dynamics simulations reveal ligand-controlled positioning of a peripheral protein complex in membranes. Nat Commun 2017; 8:6. [PMID: 28232750 PMCID: PMC5431895 DOI: 10.1038/s41467-016-0015-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 11/17/2016] [Indexed: 01/13/2023] Open
Abstract
Bryostatin is in clinical trials for Alzheimer’s disease, cancer, and HIV/AIDS eradication. It binds to protein kinase C competitively with diacylglycerol, the endogenous protein kinase C regulator, and plant-derived phorbol esters, but each ligand induces different activities. Determination of the structural origin for these differing activities by X-ray analysis has not succeeded due to difficulties in co-crystallizing protein kinase C with relevant ligands. More importantly, static, crystal-lattice bound complexes do not address the influence of the membrane on the structure and dynamics of membrane-associated proteins. To address this general problem, we performed long-timescale (400–500 µs aggregate) all-atom molecular dynamics simulations of protein kinase C–ligand–membrane complexes and observed that different protein kinase C activators differentially position the complex in the membrane due in part to their differing interactions with waters at the membrane inner leaf. These new findings enable new strategies for the design of simpler, more effective protein kinase C analogs and could also prove relevant to other peripheral protein complexes. Natural supplies of bryostatin, a compound in clinical trials for Alzheimer’s disease, cancer, and HIV, are scarce. Here, the authors perform molecular dynamics simulations to understand how bryostatin interacts with membrane-bound protein kinase C, offering insights for the design of bryostatin analogs.
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9
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Ketcham JM, Volchkov I, Chen TY, Blumberg PM, Kedei N, Lewin NE, Krische MJ. Evaluation of Chromane-Based Bryostatin Analogues Prepared via Hydrogen-Mediated C-C Bond Formation: Potency Does Not Confer Bryostatin-like Biology. J Am Chem Soc 2016; 138:13415-13423. [PMID: 27676096 PMCID: PMC5094189 DOI: 10.1021/jacs.6b08695] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesis and biological evaluation of chromane-containing bryostatin analogues WN-2-WN-7 and the previously reported salicylate-based analogue WN-8 are described. Analogues WN-2-WN-7 are prepared through convergent assembly of the chromane-containing fragment B-I with the "binding domain" fragment A-I or its C26-des-methyl congener, fragment A-II. The synthesis of fragment B-I features enantioselective double C-H allylation of 1,3-propanediol to form the C2-symmetric diol 3 and Heck cyclization of bromo-diene 5 to form the chromane core. The synthesis of salicylate WN-8 is accomplished through the union of fragments A-III and B-II. The highest binding affinities for PKCα are observed for the C26-des-methyl analogues WN-3 (Ki = 63.9 nM) and WN-7 (Ki = 63.1 nM). All analogues, WN-2-WN-8, inhibited growth of Toledo cells, with the most potent analogue being WN-7. This response, however, does not distinguish between phorbol ester-like and bryostatin-like behavior. In contrast, while many of the analogues contain a conserved C-ring in the binding domain and other features common to analogues with bryostatin-like properties, all analogues evaluated in the U937 proliferation and cell attachment assays displayed phorbol ester-like and/or toxic behavior, including WN-8, for which "bryostatin-like PKC modulatory activities" previously was suggested solely on the basis of PKC binding. These results underscore the importance of considering downstream biological effects, as tumor suppression cannot be inferred from potent PKC binding.
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Affiliation(s)
- John M. Ketcham
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
| | - Ivan Volchkov
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
| | - Te-Yu Chen
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
| | - Peter M. Blumberg
- Laboratory of Cancer Biology and Genetics, NCI, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, NCI, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Nancy E. Lewin
- Laboratory of Cancer Biology and Genetics, NCI, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Michael J. Krische
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
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10
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Haynes-Smith J, Diaz I, Billingsley KL. Modular Total Synthesis of Protein Kinase C Activator (-)-Indolactam V. Org Lett 2016; 18:2008-11. [PMID: 27074538 DOI: 10.1021/acs.orglett.6b00614] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A concise, eight-step total synthesis of (-)-indolactam V, a nanomolar agonist of protein kinase C, is reported. The synthesis relies upon an efficient copper-catalyzed amino acid arylation to establish the indole C4-nitrogen bond. This cross-coupling method is applicable to a range of hydrophobic amino acids, providing a platform for further diversification of indolactam alkaloid scaffolds and studies on their potent biological activity.
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Affiliation(s)
- Jeremy Haynes-Smith
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States
| | - Italia Diaz
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States
| | - Kelvin L Billingsley
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States
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11
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Kelsey JS, Cataisson C, Chen J, Herrmann MA, Petersen ME, Baumann DO, McGowan KM, Yuspa SH, Keck GE, Blumberg PM. Biological activity of the bryostatin analog Merle 23 on mouse epidermal cells and mouse skin. Mol Carcinog 2016; 55:2183-2195. [PMID: 26859836 DOI: 10.1002/mc.22460] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/06/2016] [Accepted: 01/06/2016] [Indexed: 12/19/2022]
Abstract
Bryostatin 1, a complex macrocyclic lactone, is the subject of multiple clinical trials for cancer chemotherapy. Although bryostatin 1 biochemically functions like the classic mouse skin tumor promoter phorbol 12-myristate 13-acetate (PMA) to bind to and activate protein kinase C, paradoxically, it fails to induce many of the typical phorbol ester responses, including tumor promotion. Intense synthetic efforts are currently underway to develop simplified bryostatin analogs that preserve the critical functional features of bryostatin 1, including its lack of tumor promoting activity. The degree to which bryostatin analogs maintain the unique pattern of biological behavior of bryostatin 1 depends on the specific cellular system and the specific response. Merle 23 is a significantly simplified bryostatin analog that retains bryostatin like activity only to a limited extent. Here, we show that in mouse epidermal cells the activity of Merle 23 was either similar to bryostatin 1 or intermediate between bryostatin 1 and PMA, depending on the specific parameter examined. We then examined the hyperplastic and tumor promoting activity of Merle 23 on mouse skin. Merle 23 showed substantially reduced hyperplasia and was not tumor promoting at a dose comparable to that for PMA. These results suggest that there may be substantial flexibility in the design of bryostatin analogs that retain its lack of tumor promoting activity. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jessica S Kelsey
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Christophe Cataisson
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Jinqiu Chen
- Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Michelle A Herrmann
- Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Mark E Petersen
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - David O Baumann
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - Kevin M McGowan
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - Stuart H Yuspa
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Gary E Keck
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
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12
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Kedei N, Kraft MB, Keck GE, Herald CL, Melody N, Pettit GR, Blumberg PM. Neristatin 1 provides critical insight into bryostatin 1 structure-function relationships. JOURNAL OF NATURAL PRODUCTS 2015; 78:896-900. [PMID: 25808573 PMCID: PMC4415049 DOI: 10.1021/acs.jnatprod.5b00094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Indexed: 06/04/2023]
Abstract
Bryostatin 1, a complex macrocyclic lactone isolated from Bugula neritina, has been the subject of multiple clinical trials for cancer. Although it functions as an activator of protein kinase C (PKC) in vitro, bryostatin 1 paradoxically antagonizes most responses to the prototypical PKC activator, the phorbol esters. The bottom half of the bryostatin 1 structure has been shown to be sufficient to confer binding to PKC. In contrast, we have previously shown that the top half of the bryostatin 1 structure is necessary for its unique biological behavior to antagonize phorbol ester responses. Neristatin 1 comprises a top half similar to that of bryostatin 1 together with a distinct bottom half that confers PKC binding. We report here that neristatin 1 is bryostatin 1-like, not phorbol ester-like, in its biological activity on U937 promyelocytic leukemia cells. We conclude that the top half of the bryostatin 1 structure is largely sufficient for bryostatin 1-like activity, provided the molecule also possesses an appropriate PKC binding domain.
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Affiliation(s)
- Noemi Kedei
- Laboratory
of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892-4255, United States
| | - Matthew B. Kraft
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Gary E. Keck
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Cherry L. Herald
- Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, United States
| | - Noeleen Melody
- Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, United States
| | - George R. Pettit
- Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, United States
| | - Peter M. Blumberg
- Laboratory
of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892-4255, United States
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13
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Andrews IP, Ketcham JM, Blumberg PM, Kedei N, Lewin N, Peach ML, Krische MJ. Synthesis of seco-B-ring bryostatin analogue WN-1 via C-C bond-forming hydrogenation: critical contribution of the B-ring in determining bryostatin-like and phorbol 12-myristate 13-acetate-like properties. J Am Chem Soc 2014; 136:13209-16. [PMID: 25207655 PMCID: PMC4183601 DOI: 10.1021/ja507825s] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Indexed: 01/31/2023]
Abstract
The seco-B-ring bryostatin analogue, macrodiolide WN-1, was prepared in 17 steps (longest linear sequence) and 30 total steps with three bonds formed via hydrogen-mediated C-C coupling. This synthetic route features a palladium-catalyzed alkoxycarbonylation of a C2-symmetric diol to form the C9-deoxygenated bryostatin A-ring. WN-1 binds to PKCα (Ki = 16.1 nM) and inhibits the growth of multiple leukemia cell lines. Although structural features of the WN-1 A-ring and C-ring are shared by analogues that display bryostatin-like behavior, WN-1 displays PMA-like behavior in U937 cell attachment and proliferation assays, as well as in K562 and MV-4-11 proliferation assays. Molecular modeling studies suggest the pattern of internal hydrogen bonds evident in bryostatin 1 is preserved in WN-1, and that upon docking WN-1 into the crystal structure of the C1b domain of PKCδ, the binding mode of bryostatin 1 is reproduced. The collective data emphasize the critical contribution of the B-ring to the function of the upper portion of the molecule in conferring a bryostatin-like pattern of biological activity.
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Affiliation(s)
- Ian P. Andrews
- Department
of Chemistry and Biochemistry, University
of Texas at Austin, Austin, Texas 78712, United States
| | - John M. Ketcham
- Department
of Chemistry and Biochemistry, University
of Texas at Austin, Austin, Texas 78712, United States
| | - Peter M. Blumberg
- Laboratory
of Cancer Biology and Genetics, National
Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, United States
| | - Noemi Kedei
- Laboratory
of Cancer Biology and Genetics, National
Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, United States
| | - Nancy
E. Lewin
- Laboratory
of Cancer Biology and Genetics, National
Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, United States
| | - Megan L. Peach
- Basic Science Program,
Leidos Biomedical Research, Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Michael J. Krische
- Department
of Chemistry and Biochemistry, University
of Texas at Austin, Austin, Texas 78712, United States
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14
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Arthur C. Cope Scholar Awards. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201405981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Arthur C. Cope Scholar Awards. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/anie.201405981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Garcia LC, Donadío LG, Mann E, Kolusheva S, Kedei N, Lewin NE, Hill CS, Kelsey JS, Yang J, Esch TE, Santos M, Peach ML, Kelley JA, Blumberg PM, Jelinek R, Marquez VE, Comin MJ. Synthesis, biological, and biophysical studies of DAG-indololactones designed as selective activators of RasGRP. Bioorg Med Chem 2014; 22:3123-40. [PMID: 24794745 PMCID: PMC4104769 DOI: 10.1016/j.bmc.2014.04.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/05/2014] [Accepted: 04/14/2014] [Indexed: 01/21/2023]
Abstract
The development of selective agents capable of discriminating between protein kinase C (PKC) isoforms and other diacylglycerol (DAG)-responsive C1 domain-containing proteins represents an important challenge. Recent studies have highlighted the role that Ras guanine nucleotide-releasing protein (RasGRP) isoforms play both in immune responses as well as in the development of prostate cancer and melanoma, suggesting that the discovery of selective ligands could have potential therapeutic value. Thus far, the N-methyl-substituted indololactone 1 is the agonist with the highest reported potency and selectivity for RasGRP relative to PKC. Here we present the synthesis, binding studies, cellular assays and biophysical analysis of interactions with model membranes of a family of regioisomers of 1 (compounds 2-5) that differ in the position of the linkage between the indole ring and the lactone moiety. These structural variations were studied to explore the interaction of the active complex (C1 domain-ligand) with cellular membranes, which is believed to be an important factor for selectivity in the activation of DAG-responsive C1 domain containing signaling proteins. All compounds were potent and selective activators of RasGRP when compared to PKCα with selectivities ranging from 6 to 65 fold. However, the parent compound 1 was appreciably more selective than any of the other isomers. In intact cells, modest differences in the patterns of translocation of the C1 domain targets were observed. Biophysical studies using giant vesicles as model membranes did show substantial differences in terms of molecular interactions impacting lipid organization, dynamics and membrane insertion. However, these differences did not yield correspondingly large changes in patterns of biological response, at least for the parameters examined.
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Affiliation(s)
- Lia C Garcia
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Lucia Gandolfi Donadío
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Ella Mann
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Sofiya Kolusheva
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Colin S Hill
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jessica S Kelsey
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jing Yang
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Timothy E Esch
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Marina Santos
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Megan L Peach
- Basic Science Program, Leidos Biomedical, Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702, USA
| | - James A Kelley
- Chemical Biology Laboratory, Molecular Discovery Program, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Raz Jelinek
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Victor E Marquez
- Chemical Biology Laboratory, Molecular Discovery Program, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Maria J Comin
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina.
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17
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Kedei N, Chen JQ, Herrmann MA, Telek A, Goldsmith PK, Petersen ME, Keck GE, Blumberg PM. Molecular systems pharmacology: isoelectric focusing signature of protein kinase Cδ provides an integrated measure of its modulation in response to ligands. J Med Chem 2014; 57:5356-69. [PMID: 24906106 PMCID: PMC4216220 DOI: 10.1021/jm500417b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Protein
kinase C (PKC), a validated therapeutic target for cancer
chemotherapy, provides a paradigm for assessing structure–activity
relations, where ligand binding has multiple consequences for a target.
For PKC, ligand binding controls not only PKC activation and multiple
phosphorylations but also subcellular localization, affecting subsequent
signaling. Using a capillary isoelectric focusing immunoassay system,
we could visualize a high resolution isoelectric focusing signature
of PKCδ upon stimulation by ligands of the phorbol ester and
bryostatin classes. Derivatives that possessed different physicochemical
characteristics and induced different patterns of biological response
generated different signatures. Consistent with different patterns
of PKCδ localization as one factor linked to these different
signatures, we found different signatures for activated PKCδ
from the nuclear and non-nuclear fractions. We conclude that the capillary
isoelectric focusing immunoassay system may provide a window into
the integrated consequences of ligand binding and thus afford a powerful
platform for compound development.
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Affiliation(s)
- Noemi Kedei
- Laboratory of Cancer Biology and Genetics, ‡Collaborative Protein Technology Resource, Laboratory of Cell Biology, and §Office of Science and Technology Partnerships, Center for Cancer Research, National Cancer Institute , Bethesda, Maryland 20892, United States
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18
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Kelsey JS, Geczy T, Lewin NE, Kedei N, Hill CS, Selezneva JS, Valle CJ, Woo W, Gorshkova I, Blumberg PM. Charge density influences C1 domain ligand affinity and membrane interactions. Chembiochem 2014; 15:1131-1144. [PMID: 24777910 DOI: 10.1002/cbic.201400041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Indexed: 12/25/2022]
Abstract
The C1 domain, which represents the recognition motif on protein kinase C for the lipophilic second messenger diacylglycerol and its ultrapotent analogues, the phorbol esters, has emerged as a promising therapeutic target for cancer and other indications. Potential target selectivity is markedly enhanced both because binding reflects ternary complex formation between the ligand, C1 domain, and phospholipid, and because binding drives membrane insertion of the C1 domain, permitting aspects of the C1 domain surface outside the binding site, per se, to influence binding energetics. Here, focusing on charged residues identified in atypical C1 domains which contribute to their loss of ligand binding activity, we showed that increasing charge along the rim of the binding cleft of the protein kinase C δ C1 b domain raises the requirement for anionic phospholipids. Correspondingly, it shifts the selectivity of C1 domain translocation to the plasma membrane, which is more negatively charged than internal membranes. This change in localization is most pronounced in the case of more hydrophilic ligands, which provide weaker membrane stabilization than do the more hydrophobic ligands and thus contributes an element to the structure-activity relations for C1 domain ligands. Coexpressing pairs of C1-containing constructs with differing charges each expressing a distinct fluorescent tag provided a powerful tool to demonstrate the effect of increasing charge in the C1 domain.
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Affiliation(s)
- Jessica S Kelsey
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Tamas Geczy
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Colin S Hill
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Julia S Selezneva
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Christopher J Valle
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Wonhee Woo
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
| | - Inna Gorshkova
- Biomedical Engineering and Physical Science Share Resource Program, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, U.S.A
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute Building 37, Room 4048, 37 Convent Drive MSC 4255, Bethesda, MD 20892-4255, U.S.A
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19
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Song X, Lopez-Campistrous A, Sun L, Dower NA, Kedei N, Yang J, Kelsey JS, Lewin NE, Esch TE, Blumberg PM, Stone JC. RasGRPs are targets of the anti-cancer agent ingenol-3-angelate. PLoS One 2013; 8:e72331. [PMID: 23991094 PMCID: PMC3749120 DOI: 10.1371/journal.pone.0072331] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 07/08/2013] [Indexed: 11/26/2022] Open
Abstract
Ingenol-3–angelate (I3A) is a non-tumor promoting phorbol ester-like compound identified in the sap of Euphoria peplus. Similar to tumor promoting phorbol esters, I3A is a diacylglycerol (DAG) analogue that binds with high affinity to the C1 domains of PKCs, recruits PKCs to cellular membranes and promotes enzyme activation. Numerous anti-cancer activities have been attributed to I3A and ascribed to I3A’s effects on PKCs. We show here that I3A also binds to and activates members of the RasGRP family of Ras activators leading to robust elevation of Ras-GTP and engagement of the Raf-Mek-Erk kinase cascade. In response to I3A, recombinant proteins consisting of GFP fused separately to full-length RasGRP1 and RasGRP3 were rapidly recruited to cell membranes, consistent with direct binding of the compound to RasGRP’s C1 domain. In the case of RasGRP3, IA3 treatment led to positive regulatory phosphorylation on T133 and activation of the candidate regulatory kinase PKCδ. I3A treatment of select B non-Hodgkin’s lymphoma cell lines resulted in quantitative and qualitative changes in Bcl-2 family member proteins and induction of apoptosis, as previously demonstrated with the DAG analogue bryostatin 1 and its synthetic analogue pico. Our results offer further insights into the anticancer properties of I3A, support the idea that RasGRPs represent potential cancer therapeutic targets along with PKC, and expand the known range of ligands for RasGRP regulation.
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Affiliation(s)
- Xiaohua Song
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | | | - Lucy Sun
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Nancy A. Dower
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jing Yang
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jessica S. Kelsey
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nancy E. Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tim E. Esch
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Peter M. Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - James C. Stone
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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20
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Abstract
PKC (protein kinase C) has been in the limelight since the discovery three decades ago that it acts as a major receptor for the tumour-promoting phorbol esters. Phorbol esters, with their potent ability to activate two of the three classes of PKC isoenzymes, have remained the best pharmacological tool for directly modulating PKC activity. However, with the discovery of other phorbol ester-responsive proteins, the advent of various small-molecule and peptide modulators, and the need to distinguish isoenzyme-specific activity, the pharmacology of PKC has become increasingly complex. Not surprisingly, many of the compounds originally touted as direct modulators of PKC have subsequently been shown to hit many other cellular targets and, in some cases, not even directly modulate PKC. The complexities and reversals in PKC pharmacology have led to widespread confusion about the current status of the pharmacological tools available to control PKC activity. In the present review, we aim to clarify the cacophony in the literature regarding the current state of bona fide and discredited cellular PKC modulators, including activators, small-molecule inhibitors and peptides, and also address the use of genetically encoded reporters and of PKC mutants to measure the effects of these drugs on the spatiotemporal dynamics of signalling by specific isoenzymes.
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Affiliation(s)
- Alyssa X. Wu-Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0721, (858) 534-4527, Fax: (858) 822-5888
| | - Alexandra C. Newton
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0721, (858) 534-4527, Fax: (858) 822-5888
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21
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Kedei N, Lewin NE, Géczy T, Selezneva J, Braun DC, Chen J, Herrmann MA, Heldman MR, Lim L, Mannan P, Garfield SH, Poudel YB, Cummins TJ, Rudra A, Blumberg PM, Keck GE. Biological profile of the less lipophilic and synthetically more accessible bryostatin 7 closely resembles that of bryostatin 1. ACS Chem Biol 2013; 8:767-77. [PMID: 23369356 DOI: 10.1021/cb300671s] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bryostatins are a group of 20 macrolides isolated by Pettit and co-workers from the marine organism Bugula neritina. Bryostatin 1, the flagship member of the family, has been the subject of intense chemical and biological investigations due to its remarkably diverse biological activities, including promising indications as therapy for cancer, Alzheimer's disease, and HIV. Other bryostatins, however, have attracted far less attention, most probably due to their relatively low natural abundance and associated scarcity of supply. Among all macrolides in this family, bryostatin 7 is biologically the most potent protein kinase C (PKC) ligand (in terms of binding affinity) and also the first bryostatin to be synthesized in the laboratory. Nonetheless, almost no biological studies have been carried out on this agent. We describe herein the total synthesis of bryostatin 7 based on our pyran annulation technology, which allows for the first detailed biological characterizations of bryostatin 7 with side-by-side comparisons to bryostatin 1. The results suggest that the more easily synthesized and less lipophilic bryostatin 7 may be an effective surrogate for bryostatin 1.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Yam B. Poudel
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt
Lake City, Utah 84112, United States
| | - Thomas J. Cummins
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt
Lake City, Utah 84112, United States
| | - Arnab Rudra
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt
Lake City, Utah 84112, United States
| | | | - Gary E. Keck
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt
Lake City, Utah 84112, United States
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22
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Kedei N, Telek A, Michalowski AM, Kraft MB, Li W, Poudel YB, Rudra A, Petersen ME, Keck GE, Blumberg PM. Comparison of transcriptional response to phorbol ester, bryostatin 1, and bryostatin analogs in LNCaP and U937 cancer cell lines provides insight into their differential mechanism of action. Biochem Pharmacol 2013; 85:313-24. [PMID: 23146662 PMCID: PMC3553297 DOI: 10.1016/j.bcp.2012.10.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 10/03/2012] [Accepted: 10/05/2012] [Indexed: 11/23/2022]
Abstract
Bryostatin 1, like the phorbol esters, binds to and activates protein kinase C (PKC) but paradoxically antagonizes many but not all phorbol ester responses. Previously, we have compared patterns of biological response to bryostatin 1, phorbol ester, and the bryostatin 1 derivative Merle 23 in two human cancer cell lines, LNCaP and U937. Bryostatin 1 fails to induce a typical phorbol ester biological response in either cell line, whereas Merle 23 resembles phorbol ester in the U937 cells and bryostatin 1 in the LNCaP cells. Here, we have compared the pattern of their transcriptional response in both cell lines. We examined by qPCR the transcriptional response as a function of dose and time for a series of genes regulated by PKCs. In both cell lines bryostatin 1 differed primarily from phorbol ester in having a shorter duration of transcriptional modulation. This was not due to bryostatin 1 instability, since bryostatin 1 suppressed the phorbol ester response. In both cell lines Merle 23 induced a pattern of transcription largely like that of phorbol ester although with a modest reduction at later times in the LNCaP cells, suggesting that the difference in biological response of the two cell lines to Merle 23 lies downstream of this transcriptional regulation. For a series of bryostatins and analogs which ranged from bryostatin 1-like to phorbol ester-like in activity on the U937 cells, the duration of transcriptional response correlated with the pattern of biological activity, suggesting that this may provide a robust platform for structure activity analysis.
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Affiliation(s)
- N Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA.
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