1
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Mason CS, Avis T, Hu C, Nagalingam N, Mudaliar M, Coward C, Begum K, Gajewski K, Alam MJ, Bassères E, Moss S, Reich S, Duperchy E, Fox KR, Garey KW, Powell DJ. The Novel DNA Binding Mechanism of Ridinilazole, a Precision Clostridiodes difficile Antibiotic. Antimicrob Agents Chemother 2023; 67:e0156322. [PMID: 37093023 DOI: 10.1128/aac.01563-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Clostridioides difficile infection (CDI) causes substantial morbidity and mortality worldwide with limited antibiotic treatment options. Ridinilazole is a precision bisbenzimidazole antibiotic being developed to treat CDI and reduce unacceptably high rates of infection recurrence in patients. Although in late clinical development, the precise mechanism of action by which ridinilazole elicits its bactericidal activity has remained elusive. Here, we present conclusive biochemical and structural data to demonstrate that ridinilazole has a primary DNA binding mechanism, with a co-complex structure confirming binding to the DNA minor groove. Additional RNA-seq data indicated early pleiotropic changes to transcription, with broad effects on multiple C. difficile compartments and significant effects on energy generation pathways particularly. DNA binding and genomic localization was confirmed through confocal microscopy utilizing the intrinsic fluorescence of ridinilazole upon DNA binding. As such, ridinilazole has the potential to be the first antibiotic approved with a DNA minor groove binding mechanism of action.
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Affiliation(s)
| | - Tim Avis
- Summit Therapeutics, Cambridge, United Kingdom
| | - Chenlin Hu
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | | | | | | | - Khurshida Begum
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Kathleen Gajewski
- Department of Biology & Biochemistry, University of Houston Colleges of Natural Sciences and Mathematics, Houston, Texas, USA
| | - M Jahangir Alam
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Eugenie Bassères
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | | | | | | | - Keith R Fox
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
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2
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Prescott TAK, Anaissi-Afonso L, Fox KR, Maxwell A, Panaretou B, Machín F. A simplified and easy-to-use HIP HOP assay provides insights into chalcone antifungal mechanisms of action. FEBS Lett 2022; 596:3087-3102. [PMID: 36053795 PMCID: PMC10087691 DOI: 10.1002/1873-3468.14483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 12/14/2022]
Abstract
Elucidating the mechanism of action of an antifungal or cytotoxic compound is a time-consuming process. Yeast chemogenomic profiling provides a compelling solution to the problem but is experimentally complex. Here, we demonstrate the use of a highly simplified yeast chemical genetic assay comprising just 89 yeast deletion strains, each diagnostic for a specific mechanism of action. We use the assay to investigate the mechanism of action of two antifungal chalcone compounds, trans-chalcone and 4'-hydroxychalcone, and narrow down the mechanism to transcriptional stress. Crucially, the assay eliminates mechanisms of action such as topoisomerase I inhibition and membrane disruption that have been suggested for related chalcone compounds. We propose this simplified assay as a useful tool to rapidly identify common off-target mechanisms.
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Affiliation(s)
| | - Laura Anaissi-Afonso
- Unidad de Investigación, Hospital Universitario Ntra Sra de Candelaria, Santa Cruz de Tenerife, Spain.,Instituto de Tecnologías Biomédicas, Universidad de la Laguna, Tenerife, Spain
| | - Keith R Fox
- School of Biological Sciences, University of Southampton, UK
| | - Anthony Maxwell
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, UK
| | - Barry Panaretou
- School of Cancer and Pharmaceutical Sciences, King's College London, UK
| | - Félix Machín
- Unidad de Investigación, Hospital Universitario Ntra Sra de Candelaria, Santa Cruz de Tenerife, Spain.,Instituto de Tecnologías Biomédicas, Universidad de la Laguna, Tenerife, Spain.,Facultad de Ciencias de la Salud, Universidad Fernando Pessoa Canarias, Las Palmas de Gran Canaria, Spain
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3
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Procopiou G, Jackson PJM, di Mascio D, Auer JL, Pepper C, Rahman KM, Fox KR, Thurston DE. DNA sequence-selective G-A cross-linking ADC payloads for use in solid tumour therapies. Commun Biol 2022; 5:741. [PMID: 35906376 PMCID: PMC9338023 DOI: 10.1038/s42003-022-03633-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 06/24/2022] [Indexed: 11/11/2022] Open
Abstract
Antibody-Drug Conjugates (ADCs) are growing in importance for the treatment of both solid and haematological malignancies. There is a demand for new payloads with novel mechanisms of action that may offer enhanced therapeutic efficacy, especially in patients who develop resistance. We report here a class of Cyclopropabenzindole-Pyridinobenzodiazepine (CBI-PDD) DNA cross-linking payloads that simultaneously alkylate guanine (G) and adenine (A) bases in the DNA minor groove with a defined sequence selectivity. The lead payload, FGX8-46 (6), produces sequence-selective G-A cross-links and affords cytotoxicity in the low picomolar region across a panel of 11 human tumour cell lines. When conjugated to the antibody cetuximab at an average Drug-Antibody Ratio (DAR) of 2, an ADC is produced with significant antitumour activity at 1 mg/kg in a target-relevant human tumour xenograft mouse model with an unexpectedly high tolerability (i.e., no weight loss observed at doses as high as 45 mg/kg i.v., single dose). A class of Cyclopropabenzindole-Pyridinobenzodiazepine (CBI-PDD) DNA cross-linking payloads, used in Antibody-Drug Conjugates, alkylate guanine and adenine bases in the DNA minor groove with a defined sequence selectivity.
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Affiliation(s)
- George Procopiou
- Femtogenix, Lawes Open Innovation Hub, Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Paul J M Jackson
- Femtogenix, Lawes Open Innovation Hub, Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Daniella di Mascio
- School of Biological Sciences, Life Sciences Building B85, University of Southampton, Southampton, Hampshire, SO17 1BJ, UK
| | - Jennifer L Auer
- Femtogenix, Lawes Open Innovation Hub, Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Chris Pepper
- Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX, UK
| | - Khondaker Miraz Rahman
- Femtogenix, Lawes Open Innovation Hub, Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ, UK.,School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK
| | - Keith R Fox
- School of Biological Sciences, Life Sciences Building B85, University of Southampton, Southampton, Hampshire, SO17 1BJ, UK
| | - David E Thurston
- Femtogenix, Lawes Open Innovation Hub, Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ, UK. .,School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK.
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Andriollo P, Procopiou G, di Mascio DM, Jackson PJ, Rahman KM, Fox KR, Thurston DE. Abstract 1750: Design and development of a novel highly sequence-selective guanine mono-alkylating DNA-interactive ADC payload suitable for solid tumor treatments. Cancer Res 2022. [DOI: 10.1158/1538-7445.am2022-1750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Antibody-Drug Conjugates (ADCs) are a fast-growing class of targeted cancer therapeutic agents with over ten approved and greater than 100 in various stages of clinical development.
The pyridinobenzodiazepines (PDDs) are a new class of DNA-interactive sequence-selective Guanine mono-alkylating ADC payloads which contain a sequence recognition component with sufficient span to guide them to specific DNA sequences (e.g., transcription factor binding sites).
A high potency PDD, FGX15-147, has been developed that contains a bi-aryl moiety capable of forming an intramolecular ‘sigma-hole’ interaction with DNA bases, thus providing the molecule with a unique sequence-selectivity profile when compared to other DNA-interactive agents. DNA footprinting data will be presented indicating that the molecule, which spans 8-9 DNA base pairs in the minor groove, has an increased sequence selectivity compared with related analogues, preferring DNA regions containing two guanines 2-4 base pairs apart. FGX15-147 is highly cytotoxic in vitro (e.g., IC50 = 0.30 nM in SW60; 1.6 nM in LIM1215 and 0.142 nM in SW48, after 96 hours incubation), and is thought to exert its activity through a combination of DNA alkylation and inhibiting the binding of important oncogenic transcription factors such as Hypoxia Inducible Factor (HIF) to DNA (demonstrated through an in vitro Transcription Factor Array assay). HIF is known to be involved in the development of a large number of solid malignancies, including pancreatic cancer.
To explore the utility of FGX15-147 as an ADC payload, it was conjugated to trastuzumab in a stochastic manner (DAR 1.6) using a Maleimide-Valine-Alanine linker construct. The resulting ADC exhibited significant in vivo efficacy in a low copy number HER2+ pancreatic cancer Human Tumor Xenograft model using BALB-c mice transplanted with the CAPAN-1 cell line. Complete tumor regression was observed out to 60 days after a single dose of 2 mg/kg comparing favorably to a 10 mg/kg dose of trastuzumab deruxtecan (Enhertu®) in the same study in which substantial tumor regrowth had occurred by 57 days. In a standard mouse model, the FGX15-147-based ADC had a good tolerability profile with a Maximum Tolerated Dose (MTD) of at least 16 mg/kg.
Overall, the favorable tolerability and efficacy profile of FGX15-147 in an ADC format suggests that it represents a potentially valuable approach for the treatment of solid tumors.
Citation Format: Paolo Andriollo, George Procopiou, Daniella M. di Mascio, Paul J. Jackson, Khondaker M. Rahman, Keith R. Fox, David E. Thurston. Design and development of a novel highly sequence-selective guanine mono-alkylating DNA-interactive ADC payload suitable for solid tumor treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1750.
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Affiliation(s)
| | | | | | | | | | - Keith R. Fox
- 3University of Southampton, Southampton, United Kingdom
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5
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Procopiou G, Jackson PJ, di Mascio DM, Auer JL, Andriollo P, Pysz I, Rahman KM, Fox KR, Thurston DE. Abstract 1749: A new class of DNA sequence-selective G-A cross-linking antibody-drug conjugate (ADC) payloads. Cancer Res 2022. [DOI: 10.1158/1538-7445.am2022-1749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Antibody-Drug Conjugates (ADCs) are rapidly growing in importance as a targeted cancer therapy, with over ten approved, and many currently undergoing clinical trials. ADCs comprise of a cytotoxic agent (i.e., the "payload") conjugated via a chemical linker to a tumor-targeting antibody. There is a demand for novel ADC payloads with unique mechanisms of action, enhanced tolerability profiles and improved physicochemical properties. Such payloads could lead to ADCs with therapeutic efficacy in patients resistant to other therapies, and payloads with reduced hydrophobicity should lead to improved conjugation, minimal aggregation, and higher Drug-Antibody Ratios (DARs).
We report here, studies on a novel class of Cyclopropabenzindole-Pyridinobenzodiazepine (CBI-PDD) payloads, designed through molecular modeling, which form cross-links between Guanine and Adenine bases within the DNA minor groove with defined sequence specificity. Eleven novel analogs will be described which have been structurally modified with various functional groups to allow tunable hydrophobicity, and new vectors through which antibodies may be attached. Most of these analogs are highly cytotoxic, with some exhibiting IC50 values in tumor cells down to the femtomolar range (e.g., FGX37-140, 0.9 pM in both RAJI and Jurkat cells, 72 h incubation). The DNA interactivity of these analogs has been studied using a range of methods such as gel-based DNA footprinting and cross-linking, FRET melting and Transcription Factor (TF) Array assays, the results of which will be described. Overall, the analogs appear to favor the formation of intrastrand rather than interstrand DNA cross-links and can inhibit the DNA binding of several key cancer-related transcription factors such as NFκB.
To explore the potential of these analogs as ADC payloads, one member, FGX8-46, was conjugated to the EGFR-targeting antibody Cetuximab in stochastic fashion (DAR2) to produce Cetuximab-(FGX16-11). This ADC had an unexpectedly high Maximum Tolerated Dose (MTD) in a standard mouse model of at least 45 mg/kg, perhaps reflecting the novel mechanism of action of the payload. It was then evaluated in a Human Tumor Xenograft study based on BALB/c mice transplanted with the EGFR-expressing human colon cancer cell line SW-48 using single doses ranging from 1 mg/kg to 40 mg/kg. Cetuximab-(FGX16-11) was active at all dose levels including 1 mg/kg which provided tumor suppression out to approximately three weeks. Complete tumor suppression out to 50 days was seen with 20 mg/kg.
Overall, the unique mechanism of action, potent cytotoxicity, and excellent in vivo tolerability and significant efficacy in ADC format, make the CBI-PDDs a promising new class of ADC payloads suitable for further development.
Citation Format: George Procopiou, Paul J. Jackson, Daniella M. di Mascio, Jennifer L. Auer, Paolo Andriollo, Ilona Pysz, Khondaker M. Rahman, Keith R. Fox, David E. Thurston. A new class of DNA sequence-selective G-A cross-linking antibody-drug conjugate (ADC) payloads [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1749.
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Affiliation(s)
| | | | | | | | | | - Ilona Pysz
- 1Femtogenix, Harpenden, Hertfordshire, United Kingdom
| | | | - Keith R. Fox
- 2University of Southampton, Southampton, United Kingdom
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6
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Fox KR. Michael J. Waring 9 November 1939 to 16 November 2019. Biopolymers 2021. [DOI: 10.1002/bip.23430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Keith R. Fox
- School of Biological Sciences University of Southampton Southampton UK
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7
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Oliveira LM, Long AS, Brown T, Fox KR, Weber G. Melting temperature measurement and mesoscopic evaluation of single, double and triple DNA mismatches. Chem Sci 2020; 11:8273-8287. [PMID: 34094181 PMCID: PMC8163305 DOI: 10.1039/d0sc01700k] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Unlike the canonical base pairs AT and GC, the molecular properties of mismatches such as hydrogen bonding and stacking interactions are strongly dependent on the identity of the neighbouring base pairs. As a result, due to the sheer number of possible combinations of mismatches and flanking base pairs, only a fraction of these have been studied in varying experiments or theoretical models. Here, we report on the melting temperature measurement and mesoscopic analysis of contiguous DNA mismatches in nearest-neighbours and next-nearest neighbour contexts. A total of 4032 different mismatch combinations, including single, double and triple mismatches were covered. These were compared with 64 sequences containing all combinations of canonical base pairs in the same location under the same conditions. For a substantial number of single mismatch configurations, 15%, the measured melting temperatures were higher than the least stable AT base pair. The mesoscopic calculation, using the Peyrard-Bishop model, was performed on the set of 4096 sequences, and resulted in estimates of on-site and nearest-neighbour interactions that can be correlated to hydrogen bonding and base stacking. Our results confirm many of the known properties of mismatches, including the peculiar sheared stacking of tandem GA mismatches. More intriguingly, it also reveals that a number of mismatches present strong hydrogen bonding when flanked on both sites by other mismatches. To highlight the applicability of our results, we discuss a number of practical situations such as enzyme binding affinities, thymine DNA glycosylase repair activity, and trinucleotide repeat expansions.
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Affiliation(s)
- Luciana M Oliveira
- Departamento de Física, Universidade Federal de Minas Gerais 31270-901 Belo Horizonte MG Brazil +55 31 3409 5600 +55 31 3409 6616
| | - Adam S Long
- School of Biological Sciences, University of Southampton Life Sciences Building 85 Southampton SO17 1BJ UK
| | - Tom Brown
- Department of Chemistry, University of Oxford Oxford UK
| | - Keith R Fox
- School of Biological Sciences, University of Southampton Life Sciences Building 85 Southampton SO17 1BJ UK
| | - Gerald Weber
- Departamento de Física, Universidade Federal de Minas Gerais 31270-901 Belo Horizonte MG Brazil +55 31 3409 5600 +55 31 3409 6616
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8
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Ferguson L, Bhakta S, Fox KR, Wells G, Brucoli F. Synthesis and Biological Evaluation of a Novel C8-Pyrrolobenzodiazepine (PBD) Adenosine Conjugate. A Study on the Role of the PBD Ring in the Biological Activity of PBD-Conjugates. Molecules 2020; 25:E1243. [PMID: 32164166 PMCID: PMC7179398 DOI: 10.3390/molecules25051243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 11/16/2022] Open
Abstract
Here we sought to evaluate the contribution of the PBD unit to the biological activity of PBD-conjugates and, to this end, an adenosine nucleoside was attached to the PBD A-ring C8 position. A convergent approach was successfully adopted for the synthesis of a novel C8-linked pyrrolo(2,1-c)(1,4)benzodiazepine(PBD)-adenosine(ADN) hybrid. The PBD and adenosine (ADN) moieties were synthesized separately and then linked through a pentynyl linker. To our knowledge, this is the first report of a PBD connected to a nucleoside. Surprisingly, the compound showed no cytotoxicity against murine cells and was inactive against Mycobacterium aurum and M. bovis strains and did not bind to guanine-containing DNA sequences, as shown by DNase I footprinting experiments. Molecular dynamics simulations revealed that the PBD-ADN conjugate was poorly accommodated in the DNA minor groove of two DNA sequences containing the AGA-PBD binding motif, with the adenosine moiety of the ligand preventing the covalent binding of the PBD unit to the guanine amino group of the DNA duplex. These interesting findings shed further light on the ability of the substituents attached at the C8 position of PBDs to affect and modulate the biological and biophysical properties of PBD hybrids.
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Affiliation(s)
- Lindsay Ferguson
- School of Science, University of the West of Scotland, Paisley, Scotland PA1 2BE, UK
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
| | - Sanjib Bhakta
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
| | - Keith R. Fox
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Geoff Wells
- UCL School of Pharmacy, University College London, 29/39 Brunswick Square, London WC1N 1AX, UK
| | - Federico Brucoli
- Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, UK
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9
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Sayoh I, Rusling DA, Brown T, Fox KR. DNA Structural Changes Induced by Intermolecular Triple Helix Formation. ACS Omega 2020; 5:1679-1687. [PMID: 32010842 PMCID: PMC6990630 DOI: 10.1021/acsomega.9b03776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
DNase I footprints of intermolecular DNA triplexes are often accompanied by enhanced cleavage at the 3'-end of the target site at the triplex-duplex junction. We have systematically studied the sequence dependence of this effect by examining oligonucleotide binding to sites flanked by each base in turn. For complexes with a terminal T.AT triplet, the greatest enhancement is seen with ApC, followed by ApG and ApT, with the weakest enhancement at ApA. Similar DNase I enhancements were observed for a triplex with a terminal C+.GC triplet, though with little difference between the different GpN sites. Enhanced reactivity to diethylpyrocarbonate was observed at As that flank the triplex-duplex junction at AAA or AAC but not AAG or AAT. Fluorescence melting experiments demonstrated that the flanking base affected the stability with a 4 °C difference in T m between a flanking C and G. Sequences that produced the strongest enhancement correlated with those having the lower thermal stability. These results are interpreted in terms of oligonucleotide-induced changes in DNA structure and/or flexibility.
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Affiliation(s)
- Ibrahim Sayoh
- School
of Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, U.K.
| | - David A. Rusling
- School
of Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Tom Brown
- Department
of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Keith R. Fox
- School
of Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, U.K.
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10
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Carter MLJ, Rusling DA, Gurr S, Brown T, Fox KR. Stability of the different arms of a DNA tetrahedron and its interaction with a minor groove ligand. Biophys Chem 2019; 256:106270. [PMID: 31706136 DOI: 10.1016/j.bpc.2019.106270] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/02/2019] [Accepted: 10/02/2019] [Indexed: 11/27/2022]
Abstract
DNA strands can be designed to assemble into stable three-dimensional structures, based on Watson-Crick base pairing rules. The simplest of these is the DNA tetrahedron that is composed of four oligonucleotides. We have re-designed the sequence of a DNA tetrahedron so that it contains a single (AATT) binding site for the minor groove binding ligand Hoechst 33258. We examined the stability of this structure by placing fluorescent groups within each of its edges and have shown that all the edges melt at the same temperature in the absence of the ligand. The minor groove ligand still binds to its recognition sequence within the tetrahedron and increases the melting temperature of the folded complex. This ligand-induced stabilisation is propagated into the adjacent helical arms and the tetrahedron melts as a single entity in a cooperative fashion.
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Affiliation(s)
- Michael L J Carter
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - David A Rusling
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Steven Gurr
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Tom Brown
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
| | - Keith R Fox
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
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Affiliation(s)
- Barry L Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. A3-025, Seattle, WA 98109, USA
| | - Keith R Fox
- Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
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12
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Affiliation(s)
- Barry L Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - David R Corey
- Departments of Pharmacology & Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - William S Dynan
- Departments of Biochemistry and Radiation Oncology, Emory University School of Medicine, 4127 Rollins Research Center,1510 Clifton Rd. NE, Atlanta, GA 30322, USA
| | - Keith R Fox
- Centre for Biological Sciences, University of Southampton, Life Sciences Building 85, Southampton SO17 1BJ, UK
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13
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Padroni G, Parkinson JA, Fox KR, Burley GA. Structural basis of DNA duplex distortion induced by thiazole-containing hairpin polyamides. Nucleic Acids Res 2019; 46:42-53. [PMID: 29194552 PMCID: PMC5758887 DOI: 10.1093/nar/gkx1211] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/28/2017] [Indexed: 01/05/2023] Open
Abstract
This manuscript reports the molecular basis for double-stranded DNA (dsDNA) binding of hairpin polyamides incorporating a 5-alkyl thiazole (Nt) unit. Hairpin polyamides containing an N-terminal Nt unit induce higher melting stabilisation of target dsDNA sequences relative to an archetypical hairpin polyamide incorporating an N-terminal imidazole (Im) unit. However, modification of the N-terminus from Im to Nt-building blocks results in an increase in dsDNA binding affinity but lower G-selectivity. A general G-selectivity trend is observed for Nt-containing polyamide analogues. G-selectivity increases as the steric bulk in the Nt 5-position increases. Solution-based NMR structural studies reveal differences in the modulation of the target DNA duplex of Nt-containing hairpin polyamides relative to the Im-containing archetype. A structural hallmark of an Nt polyamide•dsDNA complex is a more significant degree of major groove compression of the target dsDNA sequence relative to the Im-containing hairpin polyamide.
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Affiliation(s)
- Giacomo Padroni
- Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - John A Parkinson
- Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - Keith R Fox
- Centre for Biological Sciences, University of Southampton, Life Sciences Building 85, Southampton SO17 1BJ, UK
| | - Glenn A Burley
- Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
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Procopiou G, Auer J, Mascio DD, Fox KR, Andriollo P, Pysz I, Cascio F, Veillard N, Rahman KM, Jackson PJ, Thurston DE. Abstract 211: A new class of sequence-selective DNA cross-linking ADC payloads with increased in vivotolerability. Cancer Res 2019. [DOI: 10.1158/1538-7445.am2019-211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Although five Antibody-Drug Conjugates (ADCs) have been approved and over eighty others are in development, the majority contain payloads belonging to two classes: tubulin inhibitors and DNA interactive agents. Most DNA cross-linking payloads (e.g., the PBD dimers) have potent cytotoxicity but ADCs containing them have high hydrophobicity and a narrow therapeutic window. Thus, there is interest in developing novel payloads which benefit from a potency similar to the PBD dimers but that possess lower hydrophobicity and produce ADCs with a wider Therapeutic Index (TI). The pyridinobenzodiazepines (PDDs) are a new class of guanine-alkylating payloads, and these have been coupled to an adenine-alkylating CXI/duocarmycin pharmacophore to generate molecules that can form G-A DNA cross-links. The lead PDD-CXI payload (FGX-8-46) has a sequence-selectivity profile that differs from other DNA cross-linking agents in that it spans seven to eight base-pairs compared to six to seven for a typical PBD dimer. DNA cleavage experiments have indicated that it cleaves at discrete Adenine-containing sequences of the type 5’-XGXWWWW-3’ (X is any base; W is A/T, and the underlined bases show the cleavage points), and Transcription Factor (TF) Array studies show that it is a potent TF inhibitor, down-regulating several key oncogenic TFs (e.g., NF-κB). In in vitro cell line studies, the G-A cross-linkers have low pM cytotoxicity comparable to the PBD dimers in a wide and diverse range of cell lines, including those from both solid and haematological cancers (e.g., IC50 of ~2 pM in SW-48). This payload class is also compatible with a wide variety of linker technologies, and attachment can be made through either the PDD or CXI units. Importantly, these payloads are significantly less hydrophobic than other equivalent payload classes. ADCs have been generated by conjugating these new payloads to the EGFR-targeting antibody Cetuximab with DARs of between 1.8 and 2.2. The ADCs exhibit potent cytotoxicity in vitro, significant in vivo efficacy and substantially increased tolerability compared to other DNA cross-linking payloads (e.g., the PBD dimer Tesirine). While the G-A cross-linkers retain the cytotoxic potency of the PBD dimers, the “softer” cross-link formed compared to the G-G cross-linking PBD dimers may contribute to the enhanced tolerability profile of this molecular class. The favourable hydrophobicity profile of the PDD-CXI payloads and their ease of conjugation to antibodies, along with their significant in vitro cytotoxicity, in vivo efficacy and tolerability of ADCs produced from them, suggest that they represent a promising new class of ADC payloads.
Citation Format: George Procopiou, Jennifer Auer, Daniella di Mascio, Keith R. Fox, Paolo Andriollo, Ilona Pysz, Francesco Cascio, Nicolas Veillard, K. Miraz Rahman, Paul J. Jackson, David E. Thurston. A new class of sequence-selective DNA cross-linking ADC payloads with increased in vivotolerability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 211.
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Affiliation(s)
| | | | | | - Keith R. Fox
- 2University of Southampton, Southampton, United Kingdom
| | | | - Ilona Pysz
- 1Femtogenix, Welwyn Garden City, United Kingdom
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15
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Abstract
BACKGROUND Research has long noted higher prevalence rates of suicidal thoughts and behaviors among individuals with psychotic symptoms. Major theories have proposed several explanations to account for this association. Given the differences in the literature regarding the operationalization of psychosis and sample characteristics, a quantitative review is needed to determine to what extent and how psychosis confers risk for suicidality. METHODS We searched PsycInfo, PubMed, and GoogleScholar for studies published before 1 January 2016. To be included in the analysis, studies must have used at least one psychosis-related factor to longitudinally predict suicide ideation, attempt, or death. The initial search yielded 2541 studies. Fifty studies were retained for analysis, yielding 128 statistical tests. RESULTS Suicide death was the most commonly studied outcome (43.0%), followed by attempt (39.1%) and ideation (18.0%). The median follow-up length was 7.5 years. Overall, psychosis significantly conferred risk across three outcomes, with weighted mean ORs of 1.70 (1.39-2.08) for ideation, 1.36 (1.25-1.48) for attempt, and 1.40 (1.14-1.72) for death. Detailed analyses indicated that positive symptoms consistently conferred risk across outcomes; negative symptoms were not significantly associated with ideation, and were protective against death. Some small moderator effects were detected for sample characteristics. CONCLUSIONS Psychosis is a significant risk factor for suicide ideation, attempt, and death. The finding that positive symptoms increased suicide risk and negative symptoms seemed to decrease risk sheds light on the potential mechanisms for the association between psychosis and suicidality. We note several limitations of the literature and offer suggestions for future directions.
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Affiliation(s)
- X Huang
- Department of Psychology,Florida State University,Tallahassee, FL,USA
| | - K R Fox
- Department of Psychology,Harvard University,Cambridge, MA,USA
| | - J D Ribeiro
- Department of Psychology,Florida State University,Tallahassee, FL,USA
| | - J C Franklin
- Department of Psychology,Florida State University,Tallahassee, FL,USA
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16
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Bayne LJ, Nivar I, Goodspeed B, Wileyto P, Savage J, Shih NNC, Feldman MD, Edwards J, Clark AS, Fox KR, Matro JM, Domchek SM, Bradbury AR, Shah PD, Chislock EM, Belka GK, Wang J, Amaravadi R, Chodosh LA, DeMichele AM. Abstract OT2-07-09: Detection and targeting of minimal residual disease in breast cancer to reduce recurrence: The PENN-SURMOUNT and CLEVER trials. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-ot2-07-09] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background:
Recurrent breast cancers arise from minimal residual disease (MRD): the pool of disseminated and circulating tumor cells (DTCs and CTCs) that survive in their host following treatment of primary breast cancer. Detection of DTCs in the bone marrow (BM) after treatment is strongly associated with an increased risk of recurrence. Through the analysis of novel genetically-engineered mouse models, we have generated a substantial body of evidence that autophagy and mTOR signaling play key roles in the survival of DTCs. Moreover, administration of agents that block these pathways in mice harboring MRD reduces DTC burden and concomitantly reduces tumor recurrence, providing the rationale for translating these findings to patients (pts).
Trial Design:
The PENN-SURMOUNT screening study uses a clinically validated IHC assay (DTC-IHC) to identify at-risk pts who harbor DTCs. DTC+ pts are eligible for enrollment on the CLEVER trial, which will determine the feasibility, safety and efficacy of administering hydroxychloroquine (HCQ) and/or everolimus (EVE) in DTC+ patients to target MRD and prevent recurrence. PENN-SURMOUNT is single center, prospective cohort study of pts who have completed therapy for primary breast cancer, are within 5 yrs of diagnosis and are at increased risk for relapse by virtue of nodal positivity, triple negative disease, ER+/Oncotype DX RS ≥ 25, or residual disease after neoadjuvant therapy. Pts undergo screening BM aspirate to test for DTCs following completion of adjuvant chemo and radiotherapy. The primary objective of the study is to determine the incidence and frequency of MRD in pts who have completed primary treatment for breast cancer and to ascertain eligibility for the CLEVER recurrence prevention trial.
CLEVER is a randomized, controlled, open label phase II pilot trial. Target enrollment is 60 pts, with 15 pts allocated to each of 4 treatment arms: HCQ (600 mg BID), EVE (10mg daily), combination HCQ/EVE, or control/observation. A cycle is 28 days of continuous dosing. After a 3-month observation period, control pts will be offered HCQ/EVE therapy for 6 cycles; thus, the control group is actually a delayed treatment group and all pts will receive treatment. Pts who demonstrate persistent DTCs after 6 cycles will continue on combination therapy for an additional 6 cycles. The primary endpoint is feasibility of administering HCQ, EVE or the combination in this population. Secondary objectives include safety, efficacy (DTC reduction), and 3-year RFS. The principal translational objective is to assess the utility of a novel DTC assay, "DTC-Flow", for more sensitive detection and response to study therapy, compared to DTC-IHC. Additional translational objectives include determining whether patient DTCs, CTCs, and cell-free circulating plasma tumor DNA (ptDNA) biologically reflect the primary tumor and predict response.
As of 5/23/17, 58 patients have been enrolled to PENN SURMOUNT, with a DTC-positivity rate of 22.6%; CLEVER opened in 2/2017; 11 patients are currently enrolled. Contact information: angela.demichele@uphs.upenn.edu
Key words: Recurrence, disseminated tumor cells, dormancy, minimal residual disease, autophagy, mTOR, Everolimus, hydroxychloroquine
Citation Format: Bayne LJ, Nivar I, Goodspeed B, Wileyto P, Savage J, Shih NNC, Feldman MD, Edwards J, Clark AS, Fox KR, Matro JM, Domchek SM, Bradbury AR, Shah PD, Chislock EM, Belka GK, Wang J, Amaravadi R, Chodosh LA, DeMichele AM. Detection and targeting of minimal residual disease in breast cancer to reduce recurrence: The PENN-SURMOUNT and CLEVER trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-07-09.
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Affiliation(s)
- LJ Bayne
- University of Pennsylvania, Philadelphia, PA
| | - I Nivar
- University of Pennsylvania, Philadelphia, PA
| | - B Goodspeed
- University of Pennsylvania, Philadelphia, PA
| | - P Wileyto
- University of Pennsylvania, Philadelphia, PA
| | - J Savage
- University of Pennsylvania, Philadelphia, PA
| | - NNC Shih
- University of Pennsylvania, Philadelphia, PA
| | - MD Feldman
- University of Pennsylvania, Philadelphia, PA
| | - J Edwards
- University of Pennsylvania, Philadelphia, PA
| | - AS Clark
- University of Pennsylvania, Philadelphia, PA
| | - KR Fox
- University of Pennsylvania, Philadelphia, PA
| | - JM Matro
- University of Pennsylvania, Philadelphia, PA
| | - SM Domchek
- University of Pennsylvania, Philadelphia, PA
| | - AR Bradbury
- University of Pennsylvania, Philadelphia, PA
| | - PD Shah
- University of Pennsylvania, Philadelphia, PA
| | - EM Chislock
- University of Pennsylvania, Philadelphia, PA
| | - GK Belka
- University of Pennsylvania, Philadelphia, PA
| | - J Wang
- University of Pennsylvania, Philadelphia, PA
| | - R Amaravadi
- University of Pennsylvania, Philadelphia, PA
| | - LA Chodosh
- University of Pennsylvania, Philadelphia, PA
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Abstract
Guanine-rich DNAs can fold into four-stranded structures that contain stacks of G-quartets. Bioinformatics studies have revealed that G-rich sequences with the potential to adopt these structures are unevenly distributed throughout genomes, and are especially found in gene promoter regions. With the exception of the single-stranded telomeric DNA, all genomic G-rich sequences will always be present along with their C-rich complements, and quadruplex formation will be in competition with the corresponding Watson–Crick duplex. Quadruplex formation must therefore first require local dissociation (melting) of the duplex strands. Since negative supercoiling is known to facilitate the formation of alternative DNA structures, we have investigated G-quadruplex formation within negatively supercoiled DNA plasmids. Plasmids containing multiple copies of (G3T)n and (G3T4)n repeats, were probed with dimethylsulphate, potassium permanganate and S1 nuclease. While dimethylsulphate footprinting revealed some evidence for G-quadruplex formation in (G3T)n sequences, this was not affected by supercoiling, and permanganate failed to detect exposed thymines in the loop regions. (G3T4)n sequences were not protected from DMS and showed no reaction with permanganate. Similarly, both S1 nuclease and 2D gel electrophoresis of DNA topoisomers did not detect any supercoil-dependent structural transitions. These results suggest that negative supercoiling alone is not sufficient to drive G-quadruplex formation.
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Affiliation(s)
- Doreen A T Sekibo
- Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
| | - Keith R Fox
- Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
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Basher MA, Rahman KM, Jackson PJM, Thurston DE, Fox KR. Sequence-selective binding of C8-conjugated pyrrolobenzodiazepines (PBDs) to DNA. Biophys Chem 2017; 230:53-61. [PMID: 28941814 DOI: 10.1016/j.bpc.2017.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 11/17/2022]
Abstract
DNA footprinting and melting experiments have been used to examine the sequence-specific binding of C8-conjugates of pyrrolobenzodiazepines (PBDs) and benzofused rings including benzothiophene and benzofuran, which are attached using pyrrole- or imidazole-containing linkers. The conjugates modulate the covalent attachment points of the PBDs, so that they bind best to guanines flanked by A/T-rich sequences on either the 5'- or 3'-side. The linker affects the binding, and pyrrole produces larger changes than imidazole. Melting studies with 14-mer oligonucleotide duplexes confirm covalent attachment of the conjugates, which show a different selectivity to anthramycin and reveal that more than one ligand molecule can bind to each duplex.
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Affiliation(s)
- Mohammad A Basher
- Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
| | - Khondaker Miraz Rahman
- Institute of Pharmaceutical Science, King's College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, UK
| | - Paul J M Jackson
- Institute of Pharmaceutical Science, King's College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, UK
| | - David E Thurston
- Institute of Pharmaceutical Science, King's College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, UK
| | - Keith R Fox
- Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK.
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19
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Abstract
Summary Successful public health initiatives require multi-sector collaboration. AVONet was a UK collaborative developed to provide evidence-based strategies for active ageing. This study explored the success of AVONet in the achievement of its objectives as perceived by all partners. A convergent parallel mixed-methods design was employed, utilizing a quantitative survey and qualitative semi-structured interviews. Data collection was undertaken in September 2010, 18 months after establishing the collaborative and 6 months after funding had ceased. AVONet partners (n = 24) completed a 27-item survey. A sub-sample of four academics and four practitioners participated in semi-structured interviews. Quantitative and qualitative comparisons were made between academics' and practitioners' perceptions of success, potential for sustainability and satisfaction with structure and relationships. Participants perceived the AVONet collaborative positively. Significant between-group (academic v practitioner) differences in survey responses were observed for success (U = 19.5; p = 0.003) and structure (U = 125.5; p = 0.001). Strong positive correlations were observed between success and structure and balance between information transfer and exchange (r = 0.756; p < 0.001). Interviews confirmed positive perceptions and perceived importance of the collaborative and highlighted the need for further integration and tangible outcomes for practitioners. Suggestions to enhance sustainability were provided, such as smaller working groups and local council-led governance. Perceived success in building a multi-sectoral collaborative can be achieved during a 10-month period, despite differing needs of contributors. For collaboratives developed as a result of external funding aimed primarily at facilitating research, involvement of practitioners at an early stage may help set more comprehensive goals, supportive communication strategies, and increase potential for sustainability.
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Affiliation(s)
- H J Littlecott
- Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK
| | - K R Fox
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK.,Centre for Exercise, Nutrition and Health Sciences, University of Bristol, Bristol, UK
| | - A Stathi
- Department for Health, University of Bath, Bath, UK
| | - J L Thompson
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
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20
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Ribeiro JD, Franklin JC, Fox KR, Bentley KH, Kleiman EM, Chang BP, Nock MK. Letter to the Editor: Suicide as a complex classification problem: machine learning and related techniques can advance suicide prediction - a reply to Roaldset (2016). Psychol Med 2016; 46:2009-2010. [PMID: 27091309 DOI: 10.1017/s0033291716000611] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- J D Ribeiro
- Department of Psychology,Vanderbilt University,Nashville,TN,USA
| | - J C Franklin
- Department of Psychology,Vanderbilt University,Nashville,TN,USA
| | - K R Fox
- Department of Psychology,Harvard University,Cambridge,MA,USA
| | - K H Bentley
- Center for Anxiety and Related Disorders,Boston University,Boston, MA,USA
| | - E M Kleiman
- Department of Psychology,Harvard University,Cambridge,MA,USA
| | - B P Chang
- Department of Medicine,Columbia University,New York, NY,USA
| | - M K Nock
- Department of Psychology,Harvard University,Cambridge,MA,USA
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21
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Brucoli F, Guzman JD, Basher MA, Evangelopoulos D, McMahon E, Munshi T, McHugh TD, Fox KR, Bhakta S. DNA sequence-selective C8-linked pyrrolobenzodiazepine–heterocyclic polyamide conjugates show anti-tubercular-specific activities. J Antibiot (Tokyo) 2016; 69:843-849. [DOI: 10.1038/ja.2016.43] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 02/29/2016] [Accepted: 03/14/2016] [Indexed: 02/07/2023]
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Simmonds BAJ, Hannam KJ, Fox KR, Tobias JH. An exploration of barriers and facilitators to older adults' participation in higher impact physical activity and bone health: a qualitative study. Osteoporos Int 2016; 27:979-987. [PMID: 26556738 PMCID: PMC4767848 DOI: 10.1007/s00198-015-3376-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/19/2015] [Indexed: 11/04/2022]
Abstract
SUMMARY This qualitative study explored the acceptability of high-impact physical activity for increasing bone strength in later life. Thematic analysis established the barriers and facilitators to this physical activity. They prioritised joint over skeletal health, of which they had little concept. Interventions need to clearly communicate the rationale and benefits. INTRODUCTION The aim of this study was to explore the acceptability of doing high-impact physical activity in later life. METHODS This qualitative study was embedded within a large-scale observational study and was designed to address specific objectives and feed into a subsequent intervention. Five focus groups with physically active men and women (over 50 years) were used to develop an interview topic guide to explore the acceptability of high-impact physical activity in older men and women (over 65 years) in South West England. A total of 28 semi-structured interviews with 31 participants were then conducted and transcripts analysed thematically. RESULTS Three main barriers emerged: conceptualising bone, damage to joints and falling/safety concerns. Two main facilitators were also identified: the need to understand clear tangible benefits and incorporation of activity into everyday habits. Older adults were interested how high-impact physical activity would help to maintain their mobility, independence or social relationships. Some participants wanted tangible feedback from accelerometers, health care professionals and/or bone scans in order to develop a more intimate knowledge of their bone health. CONCLUSIONS Interventions incorporating high-impact physical activity for older adults need to communicate how this activity can impact more broadly on health and lives; that physical activity will be safe, beneficial and not damaging to their joints will need to be clearly conveyed. Ways in which high-impact physical activity can be habitualised into everyday activities, be fun and interactive may help facilitate longer term adoption.
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Affiliation(s)
- B A J Simmonds
- Musculoskeletal Research Unit, Learning and Research Building, The University of Bristol, Level 1, Southmead Hospital, Bristol, BS10 5NB, UK.
| | - K J Hannam
- Musculoskeletal Research Unit, Learning and Research Building, The University of Bristol, Level 1, Southmead Hospital, Bristol, BS10 5NB, UK
| | - K R Fox
- Centre for Exercise Nutrition and Health Sciences, School for Policy Studies, The University of Bristol, 8 Priory Road, Bristol, BS8 1TZ, UK
| | - J H Tobias
- Musculoskeletal Research Unit, Learning and Research Building, The University of Bristol, Level 1, Southmead Hospital, Bristol, BS10 5NB, UK
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Abdallah HO, Ohayon YP, Chandrasekaran AR, Sha R, Fox KR, Brown T, Rusling DA, Mao C, Seeman NC. Stabilisation of self-assembled DNA crystals by triplex-directed photo-cross-linking. Chem Commun (Camb) 2016; 52:8014-7. [DOI: 10.1039/c6cc03695c] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cross-linked crystals: triplex-forming oligonucleotides can direct cross-linking reactions within or between tiles of a DNA crystal, improving their thermal stability.
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Affiliation(s)
| | | | | | - Ruojie Sha
- Department of Chemistry
- New York University
- New York
- USA
| | - Keith R. Fox
- Centre for Biological Sciences
- University of Southampton
- Southampton
- UK
| | - Tom Brown
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
| | - David A. Rusling
- Centre for Biological Sciences
- University of Southampton
- Southampton
- UK
| | - Chengde Mao
- Department of Chemistry
- Purdue University
- West Lafayette
- USA
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Kimber ST, Brown T, Fox KR. The effect of sequence context on the activity of cytosine DNA glycosylases. Mol Biosyst 2015; 11:3273-8. [PMID: 26463365 DOI: 10.1039/c5mb00532a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have prepared single (N204D) and double (N204D:L272A) mutants of human uracil DNA glycosylase (hUDG), generating two cytosine DNA glycosylases (hCDG and hCYDG). Both these enzymes are able to excise cytosine (but not 5-methylcytosine), when this base is part of a mismatched base pair. hCDG is more active than the equivalent E. coli enzyme (eCYDG) and also has some activity when the cytosine is paired with guanine, unlike eCYDG. hCDG also has some activity against single stranded DNA, while having poor activity towards an unnatural base pair that forces the cytosine into an extrahelical conformation (in contrast to eCYDG for which a bulky base enhances the enzyme's activity). We also examined how sequence context affects the activity of these enzymes, determining the effect of flanking base pairs on cleavage efficiency. An abasic site or a hexaethylene glycol linker placed opposite the target cytosine, also causes an increase in activity compared with an AC mismatch. Flanking an AC mismatch with GC base pairs resulted in a 100-fold decrease in excision activity relative to flanking AT base pairs and the 5'-flanking base pair had a greater effect on the rate of cleavage. However, this effect is not simply due to the stability of the flanking base pairs as adjacent GT mismatches also produce low cleavage efficiency.
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Affiliation(s)
- Scott T Kimber
- Centre for Biological Sciences, Life Science Building 85, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Tom Brown
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Keith R Fox
- Centre for Biological Sciences, Life Science Building 85, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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25
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Stephenson MJ, Howell LA, O'Connell MA, Fox KR, Adcock C, Kingston J, Sheldrake H, Pors K, Collingwood SP, Searcey M. Solid-Phase Synthesis of Duocarmycin Analogues and the Effect of C-Terminal Substitution on Biological Activity. J Org Chem 2015; 80:9454-67. [PMID: 26356089 DOI: 10.1021/acs.joc.5b01373] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The duocarmycins are potent antitumor agents with potential for use in the development of antibody-drug conjugates (ADCs) as well as being clinical candidates in their own right. In this article, we describe the synthesis of a duocarmycin monomer (DSA) that is suitably protected for utilization in solid-phase synthesis. The synthesis was performed on a large scale, and the resulting racemic protected Fmoc-DSA subunit was separated by supercritical fluid chromatography (SFC) into the single enantiomers; its application to solid-phase synthesis methodology gave a series of monomeric and extended duocarmycin analogues with amino acid substituents. The DNA sequence selectivity was similar to that in previous reports for both the monomeric and extended compounds. Substitution at the C-terminus of duocarmycin caused a decrease in antiproliferative activity for all of the compounds studied. An extended compound containing an alanine at the C-terminus was converted to the primary amide or to an extended structure containing a terminal tertiary amine, but this had no beneficial effects on biological activity.
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Affiliation(s)
| | | | | | - Keith R Fox
- Centre for Biological Sciences, University of Southampton , Life Sciences Building 85, Southampton SO17 1BJ, United Kingdom
| | - Claire Adcock
- Novartis Institutes for Biomedical Research, Novartis Pharmaceuticals UK Limited , Horsham Research Centre, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom
| | - Jenny Kingston
- Novartis Institutes for Biomedical Research, Novartis Pharmaceuticals UK Limited , Horsham Research Centre, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom
| | - Helen Sheldrake
- Institute for Cancer Therapeutics, University of Bradford , Bradford, West Yorkshire BD7 1DP, United Kingdom
| | - Klaus Pors
- Institute for Cancer Therapeutics, University of Bradford , Bradford, West Yorkshire BD7 1DP, United Kingdom
| | - Stephen P Collingwood
- Novartis Institutes for Biomedical Research, Novartis Pharmaceuticals UK Limited , Horsham Research Centre, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom
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26
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Brucoli F, Guzman JD, Maitra A, James CH, Fox KR, Bhakta S. Synthesis, anti-mycobacterial activity and DNA sequence-selectivity of a library of biaryl-motifs containing polyamides. Bioorg Med Chem 2015; 23:3705-11. [PMID: 25921267 DOI: 10.1016/j.bmc.2015.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/27/2015] [Accepted: 04/02/2015] [Indexed: 02/07/2023]
Abstract
The alarming rise of extensively drug-resistant tuberculosis (XDR-TB) strains, compel the development of new molecules with novel modes of action to control this world health emergency. Distamycin analogues containing N-terminal biaryl-motifs 2(1-5)(1-7) were synthesised using a solution-phase approach and evaluated for their anti-mycobacterial activity and DNA-sequence selectivity. Thiophene dimer motif-containing polyamide 2(2,6) exhibited 10-fold higher inhibitory activity against Mycobacterium tuberculosis compared to distamycin and library member 2(5,7) showed high binding affinity for the 5'-ACATAT-3' sequence.
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Affiliation(s)
- Federico Brucoli
- School of Science and Sport, Institute of Biomedical and Environmental Health Research (IBEHR), University of the West of Scotland, Paisley PA1 2BE, UK.
| | - Juan D Guzman
- Mycobacteria Research Laboratory, Department of Biological Sciences, The Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
| | - Arundhati Maitra
- Mycobacteria Research Laboratory, Department of Biological Sciences, The Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
| | - Colin H James
- UCL School of Pharmacy, London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Keith R Fox
- Centre for Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Department of Biological Sciences, The Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
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Thøgersen-Ntoumani C, Loughren EA, Kinnafick FE, Taylor IM, Duda JL, Fox KR. Changes in work affect in response to lunchtime walking in previously physically inactive employees: A randomized trial. Scand J Med Sci Sports 2015; 25:778-87. [PMID: 25559067 DOI: 10.1111/sms.12398] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2014] [Indexed: 01/09/2023]
Abstract
Physical activity may regulate affective experiences at work, but controlled studies are needed and there has been a reliance on retrospective accounts of experience. The purpose of the present study was to examine the effect of lunchtime walks on momentary work affect at the individual and group levels. Physically inactive employees (N = 56; M age = 47.68; 92.86% female) from a large university in the UK were randomized to immediate treatment or delayed treatment (DT). The DT participants completed both a control and intervention period. During the intervention period, participants partook in three weekly 30-min lunchtime group-led walks for 10 weeks. They completed twice daily affective reports at work (morning and afternoon) using mobile phones on two randomly chosen days per week. Multilevel modeling was used to analyze the data. Lunchtime walks improved enthusiasm, relaxation, and nervousness at work, although the pattern of results differed depending on whether between-group or within-person analyses were conducted. The intervention was effective in changing some affective states and may have broader implications for public health and workplace performance.
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Affiliation(s)
- C Thøgersen-Ntoumani
- School of Psychology and Speech Pathology, Curtin University, Perth, Western Australia, Australia
| | - E A Loughren
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
| | - F-E Kinnafick
- School of Health, University of Northampton, Northampton, UK
| | - I M Taylor
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - J L Duda
- School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - K R Fox
- School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
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Kimber ST, Brown T, Fox KR. A mutant of uracil DNA glycosylase that distinguishes between cytosine and 5-methylcytosine. PLoS One 2014; 9:e95394. [PMID: 24740413 PMCID: PMC3989344 DOI: 10.1371/journal.pone.0095394] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/25/2014] [Indexed: 11/19/2022] Open
Abstract
We demonstrate that a mutant of uracil DNA glycosylase (N123D:L191A) distinguishes between cytosine and methylcytosine. Uracil DNA glycosylase (UDG) efficiently removes uracil from DNA in a reaction in which the base is flipped into the enzyme’s active site. Uracil is selected over cytosine by a pattern of specific hydrogen bonds, and thymine is excluded by steric clash of its 5-methyl group with Y66. The N123D mutation generates an enzyme that excises cytosine. This N123D:L191A mutant excises C when it is mispaired with A or opposite an abasic site, but not when it is paired with G. In contrast no cleavage is observed with any substrates that contain 5-methylcytosine. This enzyme may offer a new approach for discriminating between cytosine and 5-methylcytosine.
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Affiliation(s)
- Scott T. Kimber
- Centre for Biological Sciences, University of Southampton, Highfield, Southampton, United Kingdom
| | - Tom Brown
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, United Kingdom
| | - Keith R. Fox
- Centre for Biological Sciences, University of Southampton, Highfield, Southampton, United Kingdom
- * E-mail:
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Rusling DA, Chandrasekaran AR, Ohayon YP, Brown T, Fox KR, Sha R, Mao C, Seeman NC. Functionalizing Designer DNA Crystals with a Triple-Helical Veneer. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309914] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rusling DA, Chandrasekaran AR, Ohayon YP, Brown T, Fox KR, Sha R, Mao C, Seeman NC. Functionalizing designer DNA crystals with a triple-helical veneer. Angew Chem Int Ed Engl 2014; 53:3979-82. [PMID: 24615910 PMCID: PMC4037404 DOI: 10.1002/anie.201309914] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/15/2014] [Indexed: 11/09/2022]
Abstract
DNA is a very useful molecule for the programmed self-assembly of 2D and 3D nanoscale objects.1 The design of these structures exploits Watson-Crick hybridization and strand exchange to stitch linear duplexes into finite assemblies.2-4 The dimensions of these complexes can be increased by over five orders of magnitude through self-assembly of cohesive single-stranded segments (sticky ends).5, 6 Methods that exploit the sequence addressability of DNA nanostructures will enable the programmable positioning of components in 2D and 3D space, offering applications such as the organization of nanoelectronics,7 the direction of biological cascades,8 and the structure determination of periodically positioned molecules by X-ray diffraction.9 To this end we present a macroscopic 3D crystal based on the 3-fold rotationally symmetric tensegrity triangle3, 6 that can be functionalized by a triplex-forming oligonucleotide on each of its helical edges.
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Affiliation(s)
- David A Rusling
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ (UK).
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Abstract
DNA is the most exploited biopolymer for the programmed self-assembly of objects and devices that exhibit nanoscale-sized features. One of the most useful properties of DNA nanostructures is their ability to be functionalized with additional non-nucleic acid components. The introduction of such a component is often achieved by attaching it to an oligonucleotide that is part of the nanostructure, or hybridizing it to single-stranded overhangs that extend beyond or above the nanostructure surface. However, restrictions in nanostructure design and/or the self-assembly process can limit the suitability of these procedures. An alternative strategy is to couple the component to a DNA recognition agent that is capable of binding to duplex sequences within the nanostructure. This offers the advantage that it requires little, if any, alteration to the nanostructure and can be achieved after structure assembly. In addition, since the molecular recognition of DNA can be controlled by varying pH and ionic conditions, such systems offer tunable properties that are distinct from simple Watson-Crick hybridization. Here, we describe methodology that has been used to exploit and characterize the sequence-specific recognition of DNA nanostructures, with the aim of generating functional assemblies for bionanotechnology and synthetic biology applications.
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Affiliation(s)
- David A Rusling
- Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building 85, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Keith R Fox
- Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building 85, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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Zamudio-Vázquez R, Albericio F, Tulla-Puche J, Fox KR. Thioester Bonds of Thiocoraline Can Be Replaced with NMe-Amide Bridges without Affecting Its DNA-Binding Properties. ACS Med Chem Lett 2014; 5:45-50. [PMID: 24900772 DOI: 10.1021/ml400323x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 11/04/2013] [Indexed: 11/30/2022] Open
Abstract
In the search for new drug candidates for DNA recognition, affinity and sequence selectivity are two of the most important features. NMe-azathiocoraline, a synthetic antitumor bisintercalator derived from the natural marine product thiocoraline, shows similar potency to the parent compound, as well as possessing enhanced stability. Analysis of the DNA-binding selectivity of NMe-azathiocoraline by DNase I footprinting using universal substrates with all 136 tetranucleotides and all possible symmetrical hexanucleotide sequences revealed that, although this ligand binds to all CpG steps with lower affinities than thiocoraline, it displays additional binding to AT-rich sites. Moreover, fluorescence melting studies showed a strong interaction of the synthetic molecule with CACGTG and weaker binding to ACATGT and AGATCT. These findings demonstrate that NMe-azathiocoraline has the same mode of action as thiocoraline, mimicking its DNA-binding selectivity despite the substitution of its thioester bonds by NMe-amide bridges.
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Affiliation(s)
- Rubí Zamudio-Vázquez
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10-12, 08028 Barcelona, Spain
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Fernando Albericio
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10-12, 08028 Barcelona, Spain
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Organic
Chemistry, Faculty of Chemistry, University of Barcelona, Martí
i Franquès 1-11, 08028 Barcelona, Spain
- School of Chemistry, University of KwaZulu-Natal, 4001 Durban, South Africa
| | - Judit Tulla-Puche
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10-12, 08028 Barcelona, Spain
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Keith R. Fox
- Centre for Biological Sciences, Life Sciences Building
85, University of Southampton, Southampton SO17 1BJ, U.K
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Clark AS, Lal P, Tan KS, Heitjan DF, Feldman M, Zhang P, Gallagher M, Domchek S, Gogineni K, Keefe S, Fox KR, O'Dwyer P, DeMichele A. Abstract P2-16-20: Biomarkers to predict response to the CDK 4/6 inhibitor, palbociclib (PD 0332991) in a single-agent phase II trial in advanced breast cancer. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p2-16-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: The Cyclin D1-CDK4/6 complex is critical in regulating the G1/S checkpoint and phosphorylation of retinoblastoma protein (Rb); palbociclib is a highly-selective CDK 4/6 inhibitor. CCND1, the gene encoding Cyclin D1, is amplified in 15% of breast tumors; p16, the endogenous inhibitor of the complex is lost in up to half of breast tumors. We hypothesized that breast tumors containing either alteration or a high proliferative rate would have enhanced sensitivity to palbociclib. We conducted a single-agent, phase II trial of palbociclib in patients with advanced breast cancer (UPCC03909). In this trial, the clinical benefit rate (partial response [PR] + stable disease ≥6 months [6mSD]) was 17% (DeMichele, ASCO, 2013). The current analysis was a secondary endpoint to determine whether Rb expression, p16 loss, Ki-67 index or CCND1 amplification predicted response in the phase II trial.
Methods: Enrollment on UPCC03909 required archival tumor collection from either primary tumor or metastatic lesions. Fresh frozen paraffin-embedded (FFPE) tumor sections were tested for expression of Rb, Ki-67 and p16 by immunohistochemistry (IHC), and CCND1 amplification by fluorescence in situ hybridization. Categorical variables based on% tumor staining and intensity scores (negative defined as 0 or 1+ intensity staining, equivocal defined as 2+ staining or 3+ in <30%, or positive defined as 3+ staining intensity in 30%) were generated for Rb and p16 nuclear staining. Fisher's Exact test was used to test for associations between nominal factors, the Cochran-Mantel-Hænszel test for associations between ordinal factors, and the Cox proportional hazard model for association of progression-free survival (PFS) with biomarkers.
Results: Thirty-seven patients were enrolled; response evaluation is available in 36/37. All had FFPE tumor available for Rb, 33/37 (89%)for CCND1 amplification and 29/37 (78%) for Ki-67 and p16 analyses. For complete results see Table 1.
Conclusions: These results provide preliminary evidence that breast tumors more likely to respond to palbociclib may have higher Rb nuclear expression, lower Ki67 indices and/or loss of p16. Larger studies are needed to confirm these results.
Table 1: Biomarker Summary and ResponseBiomarkerBiomarker CategoizationFrequency (%)Response Rate PR+6mSD/total (%)PFS Hazard Ratio (95%CI)Overall Population (n = 37) 6/36 (17%) Ki-67 (n = 29)≤ 10 (n = 20)69%4/19 (21%)1.00 > 10 (n = 9)31%1/9 (11%)1.20 (0.50, 2.88)Rb (n = 37)Nuclear Score: Negative (n = 11)30%0/11 (0%)1.00 Equivocal (n = 15)40%2/14 (14.3%)0.72 (0.28, 1.84) Positive (n = 11)30%4/11 (36.4%)0.71 (0.28, 1.80)p16 (n = 29)Loss or Low Expression (n = 16)55%4/16 (25%)1.00 Moderate or High Expression (n = 13)45%1/12 (8.3%)1.08 (0.47, 2.49)CCND1 Amplification (n = 34)Non-amplified (n = 25)88%4/25 (16%)1.00 Amplified (n = 9)12%1/8 (12.5%)1.06 (0.46, 2.4)
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-20.
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Affiliation(s)
- AS Clark
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - P Lal
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - KS Tan
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - DF Heitjan
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - M Feldman
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - P Zhang
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - M Gallagher
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - S Domchek
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - K Gogineni
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - S Keefe
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - KR Fox
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - P O'Dwyer
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
| | - A DeMichele
- Abramson Cancer Center, Hospital of the University of Pennsylvania, Philadelphia, PA; Pfizer, New York, NY
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Pavey TG, Taylor AH, Fox KR, Hillsdon M, Anokye N, Campbell JL, Foster C, Green C, Moxham T, Mutrie N, Searle J, Trueman P, Taylor RS. Republished research: Effect of exercise referral schemes in primary care on physical activity and improving health outcomes: systematic review and meta-analysis. Br J Sports Med 2013; 47:526. [PMID: 23620507 DOI: 10.1136/bjsports-2012-e6462rep] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- T G Pavey
- Peninsula College of Medicine and Dentistry, Universities of Exeter and Plymouth, Exeter EX2 4SG, UK.
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Miranda E, Nordgren IK, Male AL, Lawrence CE, Hoakwie F, Cuda F, Court W, Fox KR, Townsend PA, Packham GK, Eccles SA, Tavassoli A. A cyclic peptide inhibitor of HIF-1 heterodimerization that inhibits hypoxia signaling in cancer cells. J Am Chem Soc 2013; 135:10418-25. [PMID: 23796364 PMCID: PMC3715890 DOI: 10.1021/ja402993u] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Hypoxia
inducible factor-1 (HIF-1) is a heterodimeric transcription
factor that acts as the master regulator of cellular response to reduced
oxygen levels, thus playing a key role in the adaptation, survival,
and progression of tumors. Here we report cyclo-CLLFVY,
identified from a library of 3.2 million cyclic hexapeptides using
a genetically encoded high-throughput screening platform, as an inhibitor
of the HIF-1α/HIF-1β protein–protein interaction
in vitro and in cells. The identified compound inhibits HIF-1 dimerization
and transcription activity by binding to the PAS-B domain of HIF-1α,
reducing HIF-1-mediated hypoxia response signaling in a variety of
cell lines, without affecting the function of the closely related
HIF-2 isoform. The reported cyclic peptide demonstrates the utility
of our high-throughput screening platform for the identification of
protein–protein interaction inhibitors, and forms the starting
point for the development of HIF-1 targeted cancer therapeutics.
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Affiliation(s)
- Elena Miranda
- Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Rahman KM, Jackson PJM, James CH, Basu BP, Hartley JA, de la Fuente M, Schatzlein A, Robson M, Pedley RB, Pepper C, Fox KR, Howard PW, Thurston DE. GC-targeted C8-linked pyrrolobenzodiazepine-biaryl conjugates with femtomolar in vitro cytotoxicity and in vivo antitumor activity in mouse models. J Med Chem 2013; 56:2911-35. [PMID: 23514599 DOI: 10.1021/jm301882a] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
DNA binding 4-(1-methyl-1H-pyrrol-3-yl)benzenamine (MPB) building blocks have been developed that span two DNA base pairs with a strong preference for GC-rich DNA. They have been conjugated to a pyrrolo[2,1-c][1,4]benzodiazepine (PBD) molecule to produce C8-linked PBD-MPB hybrids that can stabilize GC-rich DNA by up to 13-fold compared to AT-rich DNA. Some have subpicomolar IC50 values in human tumor cell lines and in primary chronic lymphocytic leukemia cells, while being up to 6 orders less cytotoxic in the non-tumor cell line WI38, suggesting that key DNA sequences may be relevant targets in these ultrasensitive cancer cell lines. One conjugate, 7h (KMR-28-39), which has femtomolar activity in the breast cancer cell line MDA-MB-231, has significant dose-dependent antitumor activity in MDA-MB-231 (breast) and MIA PaCa-2 (pancreatic) human tumor xenograft mouse models with insignificant toxicity at therapeutic doses. Preliminary studies suggest that 7h may sterically inhibit interaction of the transcription factor NF-κB with its cognate DNA binding sequence.
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Affiliation(s)
- Khondaker M Rahman
- Department of Pharmacy, Institute of Pharmaceutical Sciences, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
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Chalder M, Wiles NJ, Campbell J, Hollinghurst SP, Searle A, Haase AM, Taylor AH, Fox KR, Baxter H, Davis M, Thorp H, Winder R, Wright C, Calnan M, Lawlor DA, Peters TJ, Sharp DJ, Turner KM, Montgomery AA, Lewis G. A pragmatic randomised controlled trial to evaluate the cost-effectiveness of a physical activity intervention as a treatment for depression: the treating depression with physical activity (TREAD) trial. Health Technol Assess 2012; 16:1-164, iii-iv. [PMID: 22398106 DOI: 10.3310/hta16100] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The TREAting Depression with physical activity (TREAD) study investigated the cost-effectiveness of a physical activity intervention, in addition to usual general practitioner care, as a treatment for people with depression. DESIGN An individually randomised, pragmatic, multicentre randomised controlled trial with follow-up at 4, 8 and 12 months. A subset of participants took part in a qualitative study that investigated the acceptability and perceived benefits of the intervention. SETTING General practices in the Bristol and Exeter areas. PARTICIPANTS Aged 18-69 years with an International Statistical Classification of Diseases and Related Health Problems, 10th Edition (ICD-10) diagnosis of depression and scoring ≥ 14 on the Beck Depression Inventory (BDI). Those who were unable to complete self-administered questionnaires in English, with medical contraindications to physical activity or with psychosis, bipolar disorder or serious drug abuse were excluded. INTERVENTIONS We devised an intervention designed to encourage choice and autonomy in the adoption of physical activity. It consisted of up to three face-to-face and ten telephone contacts delivered by a trained physical activity facilitator over an 8-month period. MAIN OUTCOME MEASURES The primary outcome was the BDI score measured at 4 months. Secondary outcomes included depressive symptoms over the 12 months and quality of life, antidepressant use and level of physical activity. RESULTS The study recruited 361 patients, with 182 randomised to the intervention arm and 179 to the usual care arm; there was 80% retention at the 4-month follow-up. The intervention group had a slightly lower BDI score at 4 months [-0.54, 95% confidence interval (CI) -3.06 to 1.99] but there was no evidence that the intervention improved outcome for depression. Neither was there any evidence to suggest a difference in the prescription of or self-reported use of antidepressants. However, the amount of physical activity undertaken by those who had received the intervention was increased (odds ratio 2.3, 95% CI 1.3 to 3.9) and was sustained beyond the end of the intervention. From a health-care perspective, the intervention group was more costly than the usual care group, with the cost of the intervention £220 per person on average. It is therefore extremely unlikely that the intervention is cost-effective as a treatment for depression using current willingness-to-pay thresholds. CONCLUSIONS This physical activity intervention is very unlikely to lead to any clinical benefit in terms of depressive symptoms or to be a cost-effective treatment for depression. Previous research has reported some benefit and there are three possible reasons for this discrepancy: first, even though the intervention increased self-reported physical activity, the increase in activity was not sufficiently large to lead to a measurable influence; second, only more vigorous activity might be of benefit; and third, previous studies had recruited individuals with a pre-existing commitment to physical activity. Future research is needed to identify and explain the mechanisms by which depression might be effectively treated, including, in particular, specific guidance on the optimum type, intensity and duration of physical activity required to produce a therapeutic effect. TRIAL REGISTRATION Current Controlled Trials ISRCTN16900744. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 10. See the HTA programme website for further project information.
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Affiliation(s)
- M Chalder
- Academic Unit of Psychiatry, School of Social and Community Medicine, University of Bristol, Bristol, UK
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Ong CW, Liu MC, Lee KD, Chang KW, Yang YT, Tung HW, Fox KR. Synthesis of bisquinoline–pyrrole oligoamide as G-quadruplex binding ligand. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Rahman KM, Rosado H, Moreira JB, Feuerbaum EA, Fox KR, Stecher E, Howard PW, Gregson SJ, James CH, de la Fuente M, Waldron DE, Thurston DE, Taylor PW. Antistaphylococcal activity of DNA-interactive pyrrolobenzodiazepine (PBD) dimers and PBD-biaryl conjugates. J Antimicrob Chemother 2012; 67:1683-96. [PMID: 22547662 PMCID: PMC3370821 DOI: 10.1093/jac/dks127] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Objectives Pyrrolobenzodiazepine (PBD) dimers, tethered through inert propyldioxy or pentyldioxy linkers, possess potent bactericidal activity against a range of Gram-positive bacteria by virtue of their capacity to cross-link duplex DNA in sequence-selective fashion. Here we attempt to improve the antibacterial activity and cytotoxicity profile of PBD-containing conjugates by extension of dimer linkers and replacement of one PBD unit with phenyl-substituted or benzo-fused heterocycles that facilitate non-covalent interactions with duplex DNA. Methods DNase I footprinting was used to identify high-affinity DNA binding sites. A staphylococcal gene microarray was used to assess epidemic methicillin-resistant Staphylococcus aureus 16 phenotypes induced by PBD conjugates. Molecular dynamics simulations were employed to investigate the accommodation of compounds within the DNA helix. Results Increasing the length of the linker in PBD dimers led to a progressive reduction in antibacterial activity, but not in their cytotoxic capacity. Complex patterns of DNA binding were noted for extended PBD dimers. Modelling of DNA strand cross-linking by PBD dimers indicated distortion of the helix. A majority (26 of 43) of PBD-biaryl conjugates possessed potent antibacterial activity with little or no helical distortion and a more favourable cytotoxicity profile. Bactericidal activity of PBD-biaryl conjugates was determined by inability to excise covalently bound drug molecules from bacterial duplex DNA. Conclusions PBD-biaryl conjugates have a superior antibacterial profile compared with PBD dimers such as ELB-21. We have identified six PBD-biaryl conjugates as potential drug development candidates.
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Rusling DA, Nandhakumar IS, Brown T, Fox KR. Triplex-directed recognition of a DNA nanostructure assembled by crossover strand exchange. ACS Nano 2012; 6:3604-3613. [PMID: 22443318 DOI: 10.1021/nn300718z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
DNA has been widely exploited for the self-assembly of nanosized objects and arrays that offer the potential to act as scaffolds for the spatial positioning of molecular components with nanometer precision. Methods that allow the targeting of components to specific locations within these structures are therefore highly sought after. Here we report that the triplex approach to DNA recognition, which relies on the specific binding of an oligonucleotide within the major groove of double-helical DNA, can be exploited to recognize specific loci within a DNA double-crossover tile and array, a nanostructure assembled by crossover strand exchange. The oligonucleotide can be targeted to both crossover and non-crossover strands and, surprisingly, across the region spanning the crossover junction itself. Moreover, by attaching biotin to the end of the oligonucleotide, we show that streptavidin molecules can be recruited to precise locations within a DX array, with an average spacing of 31.9 (±1.3) nm. This is a promising approach that could be exploited to introduce other components compatible with oligonucleotide synthesis into the wide variety of DNA nanostructures assembled by crossover strand exchange, such as those generated by DNA origami.
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Affiliation(s)
- David A Rusling
- Centre for Biological Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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42
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Pavey TG, Anokye N, Taylor AH, Trueman P, Moxham T, Fox KR, Hillsdon M, Green C, Campbell JL, Foster C, Mutrie N, Searle J, Taylor RS. The clinical effectiveness and cost-effectiveness of exercise referral schemes: a systematic review and economic evaluation. Health Technol Assess 2012; 15:i-xii, 1-254. [PMID: 22182828 DOI: 10.3310/hta15440] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Exercise referral schemes (ERS) aim to identify inactive adults in the primary-care setting. The GP or health-care professional then refers the patient to a third-party service, with this service taking responsibility for prescribing and monitoring an exercise programme tailored to the needs of the individual. OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of ERS for people with a diagnosed medical condition known to benefit from physical activity (PA). The scope of this report was broadened to consider individuals without a diagnosed condition who are sedentary. DATA SOURCES MEDLINE; EMBASE; PsycINFO; The Cochrane Library, ISI Web of Science; SPORTDiscus and ongoing trial registries were searched (from 1990 to October 2009) and included study references were checked. METHODS Systematic reviews: the effectiveness of ERS, predictors of ERS uptake and adherence, and the cost-effectiveness of ERS; and the development of a decision-analytic economic model to assess cost-effectiveness of ERS. RESULTS Seven randomised controlled trials (UK, n = 5; non-UK, n = 2) met the effectiveness inclusion criteria, five comparing ERS with usual care, two compared ERS with an alternative PA intervention, and one to an ERS plus a self-determination theory (SDT) intervention. In intention-to-treat analysis, compared with usual care, there was weak evidence of an increase in the number of ERS participants who achieved a self-reported 90-150 minutes of at least moderate-intensity PA per week at 6-12 months' follow-up [pooled relative risk (RR) 1.11, 95% confidence interval 0.99 to 1.25]. There was no consistent evidence of a difference between ERS and usual care in the duration of moderate/vigorous intensity and total PA or other outcomes, for example physical fitness, serum lipids, health-related quality of life (HRQoL). There was no between-group difference in outcomes between ERS and alternative PA interventions or ERS plus a SDT intervention. None of the included trials separately reported outcomes in individuals with medical diagnoses. Fourteen observational studies and five randomised controlled trials provided a numerical assessment of ERS uptake and adherence (UK, n = 16; non-UK, n = 3). Women and older people were more likely to take up ERS but women, when compared with men, were less likely to adhere. The four previous economic evaluations identified suggest ERS to be a cost-effective intervention. Indicative incremental cost per quality-adjusted life-year (QALY) estimates for ERS for various scenarios were based on a de novo model-based economic evaluation. Compared with usual care, the mean incremental cost for ERS was £169 and the mean incremental QALY was 0.008, with the base-case incremental cost-effectiveness ratio at £20,876 per QALY in sedentary people without a medical condition and a cost per QALY of £14,618 in sedentary obese individuals, £12,834 in sedentary hypertensive patients, and £8414 for sedentary individuals with depression. Estimates of cost-effectiveness were highly sensitive to plausible variations in the RR for change in PA and cost of ERS. LIMITATIONS We found very limited evidence of the effectiveness of ERS. The estimates of the cost-effectiveness of ERS are based on a simple analytical framework. The economic evaluation reports small differences in costs and effects, and findings highlight the wide range of uncertainty associated with the estimates of effectiveness and the impact of effectiveness on HRQoL. No data were identified as part of the effectiveness review to allow for adjustment of the effect of ERS in different populations. CONCLUSIONS There remains considerable uncertainty as to the effectiveness of ERS for increasing activity, fitness or health indicators or whether they are an efficient use of resources in sedentary people without a medical diagnosis. We failed to identify any trial-based evidence of the effectiveness of ERS in those with a medical diagnosis. Future work should include randomised controlled trials assessing the cinical effectiveness and cost-effectivenesss of ERS in disease groups that may benefit from PA. FUNDING The National Institute for Health Research Health Technology Assessment programme.
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Affiliation(s)
- T G Pavey
- Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, UK
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Ong CW, Yang YT, Liu MC, Fox KR, Liu PH, Tung HW. Synthesis of directly linked diazine isosteres of pyrrole-polyamide that photochemically cleave DNA. Org Biomol Chem 2012; 10:1040-6. [DOI: 10.1039/c1ob06803b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
In order to enhance DNA triple helix stability synthetic oligonucleotides have been developed that bear amino groups on the sugar or base. One of the most effective of these is bis-amino-U (B), which possesses 5-propargylamino and 2′-aminoethoxy modifications. Inclusion of this modified nucleotide not only greatly enhances triplex stability, but also increases the affinity for related sequences. We have used a restriction enzyme protection, selection and amplification assay (REPSA) to isolate sequences that are bound by the heavily modified 9-mer triplex-forming oligonucleotide B6CBT. The isolated sequences contain An tracts (n = 6), suggesting that the 5′-end of this TFO was responsible for successful triplex formation. DNase I footprinting with these sequences confirmed triple helix formation at these secondary targets and demonstrated no interaction with similar oligonucleotides containing T or 5-propargylamino-dU.
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Affiliation(s)
- Antonia S Cardew
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton SO17 1BJ, UK
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Lou C, Shelbourne M, Fox KR, Brown T. 2'-Aminoethoxy-2-amino-3-methylpyridine in triplex-forming oligonucleotides: high affinity, selectivity and resistance to enzymatic degradation. Chemistry 2011; 17:14851-6. [PMID: 22127905 DOI: 10.1002/chem.201102287] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Indexed: 11/11/2022]
Abstract
The phosphoramidite monomer of the C-nucleoside 2'-aminoethoxy-2-amino-3-methylpyridine (AE-MAP) has been synthesized for the first time and incorporated into triplex-forming oligonucleotides (TFOs). Ultraviolet melting and DNase I footprinting studies show that AE-MAP is a potent triplex-stabilizing monomer that is selective for GC base pairs. TFOs containing AE-MAP bind with high affinity to duplexes but only weakly to single stranded DNA. In addition, AE-MAP confers high nuclease resistance on oligonucleotides. TFOs containing AE-MAP have potential for gene knock-out and gene expression studies.
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Affiliation(s)
- Chenguang Lou
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
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Pavey TG, Taylor AH, Fox KR, Hillsdon M, Anokye N, Campbell JL, Foster C, Green C, Moxham T, Mutrie N, Searle J, Trueman P, Taylor RS. Effect of exercise referral schemes in primary care on physical activity and improving health outcomes: systematic review and meta-analysis. BMJ 2011; 343:d6462. [PMID: 22058134 PMCID: PMC3209555 DOI: 10.1136/bmj.d6462] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess the impact of exercise referral schemes on physical activity and health outcomes. Design Systematic review and meta-analysis. DATA SOURCES Medline, Embase, PsycINFO, Cochrane Library, ISI Web of Science, SPORTDiscus, and ongoing trial registries up to October 2009. We also checked study references. Study selection Design: randomised controlled trials or non-randomised controlled (cluster or individual) studies published in peer review journals. POPULATION sedentary individuals with or without medical diagnosis. Exercise referral schemes defined as: clear referrals by primary care professionals to third party service providers to increase physical activity or exercise, physical activity or exercise programmes tailored to individuals, and initial assessment and monitoring throughout programmes. Comparators: usual care, no intervention, or alternative exercise referral schemes. RESULTS Eight randomised controlled trials met the inclusion criteria, comparing exercise referral schemes with usual care (six trials), alternative physical activity intervention (two), and an exercise referral scheme plus a self determination theory intervention (one). Compared with usual care, follow-up data for exercise referral schemes showed an increased number of participants who achieved 90-150 minutes of physical activity of at least moderate intensity per week (pooled relative risk 1.16, 95% confidence intervals 1.03 to 1.30) and a reduced level of depression (pooled standardised mean difference -0.82, -1.28 to -0.35). Evidence of a between group difference in physical activity of moderate or vigorous intensity or in other health outcomes was inconsistent at follow-up. We did not find any difference in outcomes between exercise referral schemes and the other two comparator groups. None of the included trials separately reported outcomes in individuals with specific medical diagnoses. Substantial heterogeneity in the quality and nature of the exercise referral schemes across studies might have contributed to the inconsistency in outcome findings. Conclusions Considerable uncertainty remains as to the effectiveness of exercise referral schemes for increasing physical activity, fitness, or health indicators, or whether they are an efficient use of resources for sedentary people with or without a medical diagnosis.
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Affiliation(s)
- T G Pavey
- Peninsula College of Medicine and Dentistry, Universities of Exeter and Plymouth, Exeter EX2 4SG, UK.
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Fox KR, Hillsdon M, Sharp D, Cooper AR, Coulson JC, Davis M, Harris R, McKenna J, Narici M, Stathi A, Thompson JL. Neighbourhood deprivation and physical activity in UK older adults. Health Place 2011; 17:633-40. [PMID: 21292536 DOI: 10.1016/j.healthplace.2011.01.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 12/24/2010] [Accepted: 01/06/2011] [Indexed: 11/29/2022]
Abstract
The benefits of regular physical activity for older adults are now well-established but this group remain the least active sector of the population. In this paper, the association between levels of neighbourhood deprivation and physical activity was assessed. A sample of 125 males with a mean age of 77.5 (±5.6) years, and 115 females with a mean age of age 78.6 (±8.6) underwent 7-day accelerometry, a physical performance battery, and completed a daily journeys log. Univariate associations between physical activity parameters and level of deprivation of neighbourhood were extinguished in regression models controlling for age, gender, and level of educational attainment. Age, gender, educational attainment, body mass index, physical function, and frequency of journeys from the home explained between 50% and 54% of variance in activity parameters. These results suggest the importance of strategies to help older adults maintain physical function, healthy weight, and remain active in their communities.
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Affiliation(s)
- K R Fox
- Centre for Exercise, Nutrition and Health Sciences, University of Bristol, Tyndall Avenue, Bristol BS8 1TN, UK.
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Lou C, Xiao Q, Tailor RR, Ben Gaied N, Gale N, Light ME, Fox KR, Brown T. 2′-Substituted 2-amino-3-methylpyridine ribonucleosides in triplex-forming oligonucleotides: triplex stability is determined by chemical environment. Med Chem Commun 2011. [DOI: 10.1039/c1md00068c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Coulson JC, Fox KR, Lawlor DA, Trayers T. Residents' diverse perspectives of the impact of neighbourhood renewal on quality of life and physical activity engagement: improvements but unresolved issues. Health Place 2011; 17:300-10. [PMID: 21145277 PMCID: PMC3032047 DOI: 10.1016/j.healthplace.2010.11.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 07/28/2010] [Accepted: 11/08/2010] [Indexed: 11/16/2022]
Abstract
Few studies have been published on the reactions of residents to modifications of their residential landscape. We explored residents' experiences of home zone remodelling and construction of a new cycle-walkway in a deprived neighbourhood with a particular focus on aspects of quality of life and physical activity participation. Focus groups (n=5 groups, 21 individuals) were used to investigate residents' perceptions of the effects of neighbourhood change on their lives. Consultation by planners was received positively. Several aspects of the neighbourhood were perceived to have improved, including spatial aesthetics, lighting and streetscape planting. However, influence on physical activity was minimal. Car-focused behaviour and ownership remained dominant, and safety related concerns limited behavioural choices. Residents highlighted many socio-environmental challenges that remained such as sense of neighbourhood safety, poor public transport provision, people's parking behaviour locally, and problem neighbours, and these tended to dominate conversations. Infrastructural intervention may be one important part of multi-layered solutions to improved neighbourhood life.
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Affiliation(s)
- J C Coulson
- University of Bristol, Department of Exercise, Nutrition and Health Sciences, Centre for Sport, Exercise and Health, Tyndall Avenue, Bristol BS8 1TP, UK.
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