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Seo JP, Trippett JS, Huang Z, Lee S, Nouraein S, Wang RZ, Szablowski JO. Acoustically targeted measurement of transgene expression in the brain. SCIENCE ADVANCES 2024; 10:eadj7686. [PMID: 39110811 PMCID: PMC11305388 DOI: 10.1126/sciadv.adj7686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 06/28/2024] [Indexed: 08/10/2024]
Abstract
Gene expression is a critical component of brain physiology, but monitoring this expression in the living brain represents a major challenge. Here, we introduce a new paradigm called recovery of markers through insonation (REMIS) for noninvasive measurement of gene expression in the brain with cell type, spatial, and temporal specificity. Our approach relies on engineered protein markers that are produced in neurons but exit into the brain's interstitium. When ultrasound is applied to targeted brain regions, it opens the blood-brain barrier and releases these markers into the bloodstream. Once in blood, the markers can be readily detected using biochemical techniques. REMIS can noninvasively confirm gene delivery and measure endogenous signaling in specific brain sites through a simple insonation and a subsequent blood test. REMIS is reliable and demonstrated consistent improvement in recovery of markers from the brain into the blood. Overall, this work establishes a noninvasive, spatially specific method of monitoring gene delivery and endogenous signaling in the brain.
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Affiliation(s)
- Joon Pyung Seo
- Applied Physics Program, Rice University, Houston, TX, USA
| | | | - Zhimin Huang
- Department of Bioengineering, Rice University, Houston, TX, USA
| | - Sangsin Lee
- Department of Bioengineering, Rice University, Houston, TX, USA
| | - Shirin Nouraein
- Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX, USA
| | - Ryan Z. Wang
- Department of Bioengineering, Rice University, Houston, TX, USA
| | - Jerzy O. Szablowski
- Applied Physics Program, Rice University, Houston, TX, USA
- Department of Bioengineering, Rice University, Houston, TX, USA
- Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX, USA
- Rice Neuroengineering Initiative, Rice University, Houston, TX, USA
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2
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Pradhan S, Apaydin S, Bucevičius J, Gerasimaitė R, Kostiuk G, Lukinavičius G. Sequence-specific DNA labelling for fluorescence microscopy. Biosens Bioelectron 2023; 230:115256. [PMID: 36989663 DOI: 10.1016/j.bios.2023.115256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/04/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The preservation of nucleus structure during microscopy imaging is a top priority for understanding chromatin organization, genome dynamics, and gene expression regulation. In this review, we summarize the sequence-specific DNA labelling methods that can be used for imaging in fixed and/or living cells without harsh treatment and DNA denaturation: (i) hairpin polyamides, (ii) triplex-forming oligonucleotides, (iii) dCas9 proteins, (iv) transcription activator-like effectors (TALEs) and (v) DNA methyltransferases (MTases). All these techniques are capable of identifying repetitive DNA loci and robust probes are available for telomeres and centromeres, but visualizing single-copy sequences is still challenging. In our futuristic vision, we see gradual replacement of the historically important fluorescence in situ hybridization (FISH) by less invasive and non-destructive methods compatible with live cell imaging. Combined with super-resolution fluorescence microscopy, these methods will open the possibility to look into unperturbed structure and dynamics of chromatin in living cells, tissues and whole organisms.
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3
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Seo JP, Trippett JS, Huang Z, Wang RZ, Lee S, Szablowski JO. Acoustically-Targeted Measurement of Transgene Expression in the Brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.23.541868. [PMID: 37292585 PMCID: PMC10245922 DOI: 10.1101/2023.05.23.541868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Gene expression is a critical component of brain physiology and activity, but monitoring this expression in the living brain represents a significant challenge. Here, we introduce a new paradigm called Recovery of Markers through InSonation (REMIS) for noninvasive measurement of gene expression in the brain with cell-type, spatial, and temporal specificity. Our approach relies on engineered protein markers that are designed to be expressed in neurons and exit into the interstitium. By applying ultrasound to targeted brain regions, these markers are released into the bloodstream, where they can be readily detected using biochemical techniques. REMIS can noninvasively confirm gene delivery and measure endogenous signaling in specific brain sites through a simple insonation and a subsequent blood test. Using REMIS, we successfully measured chemogenetic induction of neuronal activity in ultrasound-tar-geted brain regions. REMIS recovery of markers is reliable and demonstrated improved recovery of markers from the brain into the blood in every tested animal. Overall, our work establishes a noninvasive, spatially-specific means of monitoring gene delivery outcomes and endogenous signaling in mammalian brains, opening up possibilities for brain research and noninvasive monitoring of gene therapies in the brain.
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4
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Size matters: DNA binding site kinetics as a function of polyamide size. Biochimie 2022; 199:123-129. [DOI: 10.1016/j.biochi.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 11/20/2022]
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5
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DNA binding site kinetics of a large antiviral polyamide. Biochimie 2021; 185:146-154. [PMID: 33794342 DOI: 10.1016/j.biochi.2021.03.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 03/10/2021] [Accepted: 03/25/2021] [Indexed: 01/17/2023]
Abstract
Polyamides (PAs) are powerful DNA ligands that can bind the minor groove of DNA with high affinity and specificity. While the characterization of PA-DNA behavior has focused principally on hairpin PAs 6-8 rings in size, there is increasing evidence that their behavior does not necessarily reflect the complexities that are emerging from studies of larger hairpin PAs, particularly concerning sequence mismatch tolerance and observed but unaddressed high PA-target site binding stoichiometries. To explore these complexities in more detail, kinetics studies of binding a large anti-HPV hairpin polyamide to an isolated DNA recognition site are described. Using a fluorescence assay, two distinct binding phases are observed for the first time in hairpin PA literature. PA14 concentration dependence analysis indicates that the faster binding event is diffusion-controlled; the apparent, second event is significantly slower (350-1500 fold). Both association phases are sampled in 1:1 complexes, consistent with cooperative binding of two PA molecules even under this condition. Fitting of the slow phase to a biexponential model yields two λon,app that differ by 4-5-fold, which is consistent with the high mismatch tolerance and binding site stoichiometry previously observed. A/T patterns in the recognition sequence do not affect these decay constants significantly. Dissociation decay constants are among the slowest reported for hairpin PAs (10-3 s-1), independent of A/T pattern, and may point to the efficacy of PA14 as an antiviral.
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The Road Not Taken with Pyrrole-Imidazole Polyamides: Off-Target Effects and Genomic Binding. Biomolecules 2020; 10:biom10040544. [PMID: 32260120 PMCID: PMC7226143 DOI: 10.3390/biom10040544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022] Open
Abstract
The high sequence specificity of minor groove-binding N-methylpyrrole-N-methylimidazole polyamides have made significant advances in cancer and disease biology, yet there have been few comprehensive reports on their off-target effects, most likely as a consequence of the lack of available tools in evaluating genomic binding, an essential aspect that has gone seriously underexplored. Compared to other N-heterocycles, the off-target effects of these polyamides and their specificity for the DNA minor groove and primary base pair recognition require the development of new analytical methods, which are missing in the field today. This review aims to highlight the current progress in deciphering the off-target effects of these N-heterocyclic molecules and suggests new ways that next-generating sequencing can be used in addressing off-target effects.
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Yu Z, Pandian GN, Hidaka T, Sugiyama H. Therapeutic gene regulation using pyrrole-imidazole polyamides. Adv Drug Deliv Rev 2019; 147:66-85. [PMID: 30742856 DOI: 10.1016/j.addr.2019.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/22/2018] [Accepted: 02/04/2019] [Indexed: 12/13/2022]
Abstract
Recent innovations in cutting-edge sequencing platforms have allowed the rapid identification of genes associated with communicable, noncommunicable and rare diseases. Exploitation of this collected biological information has facilitated the development of nonviral gene therapy strategies and the design of several proteins capable of editing specific DNA sequences for disease control. Small molecule-based targeted therapeutic approaches have gained increasing attention because of their suggested clinical benefits, ease of control and lower costs. Pyrrole-imidazole polyamides (PIPs) are a major class of DNA minor groove-binding small molecules that can be predesigned to recognize specific DNA sequences. This programmability of PIPs allows the on-demand design of artificial genetic switches and fluorescent probes. In this review, we detail the progress in the development of PIP-based designer ligands and their prospects as advanced DNA-based small-molecule drugs for therapeutic gene modulation.
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Veras Ribeiro Filho H, Tambones IL, Mariano Gonçalves Dias M, Bernardi Videira N, Bruder M, Amorim Amato A, Migliorini Figueira AC. Modulation of nuclear receptor function: Targeting the protein-DNA interface. Mol Cell Endocrinol 2019; 484:1-14. [PMID: 30703486 DOI: 10.1016/j.mce.2019.01.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/25/2019] [Accepted: 01/25/2019] [Indexed: 02/02/2023]
Abstract
Nuclear receptors (NRs) are a superfamily of ligand-dependent transcription factors that modulate several biological processes. Traditionally, modulation of NRs has been focused on the development of ligands that recognize and bind to the ligand binding domain (LBD), resulting in activation or repression of transcription through the recruitment of coregulators. However, for more severe diseases, such as breast and prostate cancer, the conventional treatment addressing LBD modulation is not always successful, due to tumor resistance. To overcome these challenges and aiming to modulate NR activity by inhibiting the NR-DNA interaction, new studies focus on the development of molecules targeting alternative sites and domains on NRs. Here, we discuss two different approaches for this alternative NR modulation: one targeting the NR DNA binding domain (DBD); and the other targeting the DNA sites recognized by NRs. Our aim is to present the challenges and perspectives for developing specific inhibitors for each purpose, alongside with already reported examples.
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Affiliation(s)
- Helder Veras Ribeiro Filho
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, 13083-970, Brazil; Graduate Program in Biosciences and Technology of Bioactive Products, Institute of Biology, State University of Campinas (Unicamp), Campinas, 13083-970, Brazil
| | - Izabella Luisa Tambones
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, 13083-970, Brazil; Graduate Program in Biosciences and Technology of Bioactive Products, Institute of Biology, State University of Campinas (Unicamp), Campinas, 13083-970, Brazil
| | - Marieli Mariano Gonçalves Dias
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, 13083-970, Brazil; Graduate Program in Molecular and Functional Biology, Institute of Biology, State University of Campinas (Unicamp), Campinas, SP, 13083-970, Brazil
| | - Natalia Bernardi Videira
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, 13083-970, Brazil
| | - Marjorie Bruder
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, 13083-970, Brazil
| | - Angélica Amorim Amato
- Laboratory of Molecular Pharmacology, Department of Pharmaceutical Science, University of Brasilia (UnB), Brasília, DF, 70910-900, Brazil
| | - Ana Carolina Migliorini Figueira
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, 13083-970, Brazil.
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9
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A New Generation of Minor-Groove-Binding-Heterocyclic Diamidines That Recognize G·C Base Pairs in an AT Sequence Context. Molecules 2019; 24:molecules24050946. [PMID: 30866557 PMCID: PMC6429135 DOI: 10.3390/molecules24050946] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 12/17/2022] Open
Abstract
We review the preparation of new compounds with good solution and cell uptake properties that can selectively recognize mixed A·T and G·C bp sequences of DNA. Our underlying aim is to show that these new compounds provide important new biotechnology reagents as well as a new class of therapeutic candidates with better properties and development potential than other currently available agents. In this review, entirely different ways to recognize mixed sequences of DNA by modifying AT selective heterocyclic cations are described. To selectively recognize a G·C base pair an H-bond acceptor must be incorporated with AT recognizing groups as with netropsin. We have used pyridine, azabenzimidazole and thiophene-N-methylbenzimidazole GC recognition units in modules crafted with both rational design and empirical optimization. These modules can selectively and strongly recognize a single G·C base pair in an AT sequence context. In some cases, a relatively simple change in substituents can convert a heterocyclic module from AT to GC recognition selectivity. Synthesis and DNA interaction results for initial example lead modules are described for single G·C base pair recognition compounds. The review concludes with a description of the initial efforts to prepare larger compounds to recognize sequences of DNA with more than one G·C base pairs. The challenges and initial successes are described along with future directions.
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Lambert M, Jambon S, Depauw S, David-Cordonnier MH. Targeting Transcription Factors for Cancer Treatment. Molecules 2018; 23:molecules23061479. [PMID: 29921764 PMCID: PMC6100431 DOI: 10.3390/molecules23061479] [Citation(s) in RCA: 229] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 12/15/2022] Open
Abstract
Transcription factors are involved in a large number of human diseases such as cancers for which they account for about 20% of all oncogenes identified so far. For long time, with the exception of ligand-inducible nuclear receptors, transcription factors were considered as “undruggable” targets. Advances knowledge of these transcription factors, in terms of structure, function (expression, degradation, interaction with co-factors and other proteins) and the dynamics of their mode of binding to DNA has changed this postulate and paved the way for new therapies targeted against transcription factors. Here, we discuss various ways to target transcription factors in cancer models: by modulating their expression or degradation, by blocking protein/protein interactions, by targeting the transcription factor itself to prevent its DNA binding either through a binding pocket or at the DNA-interacting site, some of these inhibitors being currently used or evaluated for cancer treatment. Such different targeting of transcription factors by small molecules is facilitated by modern chemistry developing a wide variety of original molecules designed to specifically abort transcription factor and by an increased knowledge of their pathological implication through the use of new technologies in order to make it possible to improve therapeutic control of transcription factor oncogenic functions.
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Affiliation(s)
- Mélanie Lambert
- INSERM UMR-S1172-JPARC (Jean-Pierre Aubert Research Center), Lille University and Hospital Center (CHU-Lille), Institut pour la Recherche sur le Cancer de Lille (IRCL), Place de Verdun, F-59045 Lille, France.
| | - Samy Jambon
- INSERM UMR-S1172-JPARC (Jean-Pierre Aubert Research Center), Lille University and Hospital Center (CHU-Lille), Institut pour la Recherche sur le Cancer de Lille (IRCL), Place de Verdun, F-59045 Lille, France.
| | - Sabine Depauw
- INSERM UMR-S1172-JPARC (Jean-Pierre Aubert Research Center), Lille University and Hospital Center (CHU-Lille), Institut pour la Recherche sur le Cancer de Lille (IRCL), Place de Verdun, F-59045 Lille, France.
| | - Marie-Hélène David-Cordonnier
- INSERM UMR-S1172-JPARC (Jean-Pierre Aubert Research Center), Lille University and Hospital Center (CHU-Lille), Institut pour la Recherche sur le Cancer de Lille (IRCL), Place de Verdun, F-59045 Lille, France.
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11
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Geel TM, Ruiters MHJ, Cool RH, Halby L, Voshart DC, Andrade Ruiz L, Niezen-Koning KE, Arimondo PB, Rots MG. The past and presence of gene targeting: from chemicals and DNA via proteins to RNA. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170077. [PMID: 29685979 PMCID: PMC5915719 DOI: 10.1098/rstb.2017.0077] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2017] [Indexed: 12/19/2022] Open
Abstract
The ability to target DNA specifically at any given position within the genome allows many intriguing possibilities and has inspired scientists for decades. Early gene-targeting efforts exploited chemicals or DNA oligonucleotides to interfere with the DNA at a given location in order to inactivate a gene or to correct mutations. We here describe an example towards correcting a genetic mutation underlying Pompe's disease using a nucleotide-fused nuclease (TFO-MunI). In addition to the promise of gene correction, scientists soon realized that genes could be inactivated or even re-activated without inducing potentially harmful DNA damage by targeting transcriptional modulators to a particular gene. However, it proved difficult to fuse protein effector domains to the first generation of programmable DNA-binding agents. The engineering of gene-targeting proteins (zinc finger proteins (ZFPs), transcription activator-like effectors (TALEs)) circumvented this problem. The disadvantage of protein-based gene targeting is that a fusion protein needs to be engineered for every locus. The recent introduction of CRISPR/Cas offers a flexible approach to target a (fusion) protein to the locus of interest using cheap designer RNA molecules. Many research groups now exploit this platform and the first human clinical trials have been initiated: CRISPR/Cas has kicked off a new era of gene targeting and is revolutionizing biomedical sciences.This article is part of a discussion meeting issue 'Frontiers in epigenetic chemical biology'.
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Affiliation(s)
- T M Geel
- Epigenetic Editing, Dept Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - M H J Ruiters
- Epigenetic Editing, Dept Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - R H Cool
- Chemical and Pharmaceutical Biology, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - L Halby
- CNRS FRE3600 ETaC, bât IBCG, 31062 Toulouse, France
| | - D C Voshart
- Epigenetic Editing, Dept Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - L Andrade Ruiz
- Epigenetic Editing, Dept Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - K E Niezen-Koning
- Laboratory of Metabolic Diseases, Dept Laboratory Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - P B Arimondo
- CNRS FRE3600 ETaC, bât IBCG, 31062 Toulouse, France
| | - M G Rots
- Epigenetic Editing, Dept Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
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Kawamoto Y, Bando T, Sugiyama H. Sequence-specific DNA binding Pyrrole-imidazole polyamides and their applications. Bioorg Med Chem 2018; 26:1393-1411. [PMID: 29439914 DOI: 10.1016/j.bmc.2018.01.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/25/2018] [Accepted: 01/28/2018] [Indexed: 12/25/2022]
Abstract
Pyrrole-imidazole polyamides (Py-Im polyamides) are cell-permeable compounds that bind to the minor groove of double-stranded DNA in a sequence-specific manner without causing denaturation of the DNA. These compounds can be used to control gene expression and to stain specific sequences in cells. Here, we review the history, structural variations, and functional investigations of Py-Im polyamides.
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Affiliation(s)
- Yusuke Kawamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan; Institute for Integrated Cell-Material Science (iCeMS), Kyoto University, Sakyo, Kyoto 606-8501, Japan.
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Restoration of the prolyl-hydroxylase domain protein-3 oxygen-sensing mechanism is responsible for regulation of HIF2α expression and induction of sensitivity of myeloma cells to hypoxia-mediated apoptosis. PLoS One 2017; 12:e0188438. [PMID: 29206844 PMCID: PMC5716583 DOI: 10.1371/journal.pone.0188438] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 11/07/2017] [Indexed: 12/18/2022] Open
Abstract
Multiple myeloma (MM) is an incurable disease of malignant plasma B-cells that infiltrate the bone marrow (BM), resulting in bone destruction, anemia, renal impairment and infections. Physiologically, the BM microenvironment is hypoxic and this promotes MM progression and contributes to resistance to chemotherapy. Since aberrant hypoxic responses may result in the selection of more aggressive tumor phenotypes, we hypothesized that targeting the hypoxia-inducible factor (HIF) pathways will be an effective anti-MM therapeutic strategy. We demonstrated that MM cells are resistant to hypoxia-mediated apoptosis in vivo and in vitro, and that constitutive expression of HIF2α contributed to this resistance. Since epigenetic silencing of the prolyl-hydroxylase-domain-3 (PHD3) enzyme responsible for the O2-dependent regulation of HIF2α is frequently observed in MM tumors, we asked if PHD3 plays a role in regulating sensitivity to hypoxia. We found that restoring PHD3 expression using a lentivirus vector or overcoming PHD3 epigenetic silencing using a demethyltransferase inhibitor, 5-Aza-2'-deoxycytidine (5-Aza-dC), rescued O2-dependent regulation of HIF2α and restored sensitivity of MM cells to hypoxia-mediated apoptosis. This provides a rationale for targeting the PHD3-mediated regulation of the adaptive cellular hypoxic response in MM and suggests that targeting the O2-sensing pathway, alone or in combination with other anti-myeloma chemotherapeutics, may have clinical efficacy.
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14
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Synthetic genome readers target clustered binding sites across diverse chromatin states. Proc Natl Acad Sci U S A 2016; 113:E7418-E7427. [PMID: 27830652 DOI: 10.1073/pnas.1604847113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Targeting the genome with sequence-specific DNA-binding molecules is a major goal at the interface of chemistry, biology, and precision medicine. Polyamides, composed of N-methylpyrrole and N-methylimidazole monomers, are a class of synthetic molecules that can be rationally designed to "read" specific DNA sequences. However, the impact of different chromatin states on polyamide binding in live cells remains an unresolved question that impedes their deployment in vivo. Here, we use cross-linking of small molecules to isolate chromatin coupled to sequencing to map the binding of two bioactive and structurally distinct polyamides to genomes directly within live H1 human embryonic stem cells. This genome-wide view from live cells reveals that polyamide-based synthetic genome readers bind cognate sites that span a range of binding affinities. Polyamides can access cognate sites within repressive heterochromatin. The occupancy patterns suggest that polyamides could be harnessed to target loci within regions of the genome that are inaccessible to other DNA-targeting molecules.
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