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Nué-Martinez JJ, Cisneros D, Moreno-Blázquez MD, Fonseca-Berzal C, Manzano JI, Kraeutler D, Ungogo MA, Aloraini MA, Elati HAA, Ibáñez-Escribano A, Lagartera L, Herraiz T, Gamarro F, de Koning HP, Gómez-Barrio A, Dardonville C. Synthesis and Biophysical and Biological Studies of N-Phenylbenzamide Derivatives Targeting Kinetoplastid Parasites. J Med Chem 2023; 66:13452-13480. [PMID: 37729094 PMCID: PMC10578353 DOI: 10.1021/acs.jmedchem.3c00697] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Indexed: 09/22/2023]
Abstract
The AT-rich mitochondrial DNA (kDNA) of trypanosomatid parasites is a target of DNA minor groove binders. We report the synthesis, antiprotozoal screening, and SAR studies of three series of analogues of the known antiprotozoal kDNA binder 2-((4-(4-((4,5-dihydro-1H-imidazol-3-ium-2-yl)amino)benzamido)phenyl)amino)-4,5-dihydro-1H-imidazol-3-ium (1a). Bis(2-aminoimidazolines) (1) and bis(2-aminobenzimidazoles) (2) showed micromolar range activity against Trypanosoma brucei, whereas bisarylimidamides (3) were submicromolar inhibitors of T. brucei, Trypanosoma cruzi, and Leishmania donovani. None of the compounds showed relevant activity against the urogenital, nonkinetoplastid parasite Trichomonas vaginalis. We show that series 1 and 3 bind strongly and selectively to the minor groove of AT DNA, whereas series 2 also binds by intercalation. The measured pKa indicated different ionization states at pH 7.4, which correlated with the DNA binding affinities (ΔTm) for series 2 and 3. Compound 3a, which was active and selective against the three parasites and displayed adequate metabolic stability, is a fine candidate for in vivo studies.
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Affiliation(s)
- J. Jonathan Nué-Martinez
- Instituto
de Química Médica, IQM−CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
- PhD
Programme in Medicinal Chemistry, Doctoral School, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
| | - David Cisneros
- Instituto
de Química Médica, IQM−CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
- PhD
Programme in Medicinal Chemistry, Doctoral School, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
| | | | - Cristina Fonseca-Berzal
- Departamento
de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain
| | - José Ignacio Manzano
- Instituto
de Parasitología y Biomedicina “Löpez Neyra”,
IPBLN-CSIC, Parque Tecnolögico
de Ciencias de la Salud, 18016 Granada, Spain
| | - Damien Kraeutler
- Instituto
de Química Médica, IQM−CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Marzuq A. Ungogo
- Institute
of Infection, Immunity and Inflammation, College of Medical, Veterinary
and Life Sciences, University of Glasgow, G12 8TA Glasgow, U.K.
| | - Maha A. Aloraini
- Institute
of Infection, Immunity and Inflammation, College of Medical, Veterinary
and Life Sciences, University of Glasgow, G12 8TA Glasgow, U.K.
| | - Hamza A. A. Elati
- Institute
of Infection, Immunity and Inflammation, College of Medical, Veterinary
and Life Sciences, University of Glasgow, G12 8TA Glasgow, U.K.
| | - Alexandra Ibáñez-Escribano
- Departamento
de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain
| | - Laura Lagartera
- Instituto
de Química Médica, IQM−CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Tomás Herraiz
- Instituto
de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN−CSIC, José Antonio Novais 10, Ciudad
Universitaria, 28040 Madrid, Spain
| | - Francisco Gamarro
- Instituto
de Parasitología y Biomedicina “Löpez Neyra”,
IPBLN-CSIC, Parque Tecnolögico
de Ciencias de la Salud, 18016 Granada, Spain
| | - Harry P. de Koning
- Institute
of Infection, Immunity and Inflammation, College of Medical, Veterinary
and Life Sciences, University of Glasgow, G12 8TA Glasgow, U.K.
| | - Alicia Gómez-Barrio
- Departamento
de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain
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Razzaq M, Han JH, Ravichandran S, Kim J, Bae JY, Park MS, Kannappan S, Chung WC, Ahn JH, Song MJ, Kim KK. Stabilization of RNA G-quadruplexes in the SARS-CoV-2 genome inhibits viral infection via translational suppression. Arch Pharm Res 2023; 46:598-615. [PMID: 37563335 DOI: 10.1007/s12272-023-01458-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 07/28/2023] [Indexed: 08/12/2023]
Abstract
The G-quadruplex (G4) formed in single-stranded DNAs or RNAs plays a key role in diverse biological processes and is considered as a potential antiviral target. In the genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), 25 putative G4-forming sequences are predicted; however, the effects of G4-binding ligands on SARS-CoV-2 replication have not been studied in the context of viral infection. In this study, we investigated whether G4-ligands suppressed SARS-CoV-2 replication and whether their antiviral activity involved stabilization of viral RNA G4s and suppression of viral gene expression. We found that pyridostatin (PDS) suppressed viral gene expression and genome replication as effectively as the RNA polymerase inhibitor remdesivir. Biophysical analyses revealed that the 25 predicted G4s in the SARS-CoV-2 genome formed a parallel G4 structure. In particular, G4-644 and G4-3467 located in the 5' region of ORF1a, formed a G4 structure that could be effectively stabilized by PDS. We also showed that PDS significantly suppressed translation of the reporter genes containing these G4s. Taken together, our results demonstrate that stabilization of RNA G4s by PDS in the SARS-CoV-2 genome inhibits viral infection via translational suppression, highlighting the therapeutic potential of G4-ligands in SARS-CoV-2 infection.
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Affiliation(s)
- Maria Razzaq
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Ji Ho Han
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Subramaniyam Ravichandran
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
- Department of Biology, Stanford University, Stanford, United States of America
| | - Jaehyun Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Joon-Yong Bae
- Department of Microbiology, Institute for Viral Diseases, Biosafety Center, College of Medicine, Korea University, Seoul, 02841, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, Institute for Viral Diseases, Biosafety Center, College of Medicine, Korea University, Seoul, 02841, Republic of Korea
| | - Shrute Kannappan
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Woo-Chang Chung
- Department of Microbiology, Graduate School of Basic Medical Science (GSBMS), Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Jin-Hyun Ahn
- Department of Microbiology, Graduate School of Basic Medical Science (GSBMS), Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
| | - Moon Jung Song
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
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Floyd TG, Song JI, Hapeshi A, Laroque S, Hartlieb M, Perrier S. Bottlebrush copolymers for gene delivery: influence of architecture, charge density, and backbone length on transfection efficiency. J Mater Chem B 2022; 10:3696-3704. [PMID: 35441653 DOI: 10.1039/d2tb00490a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of polymer architecture of polycations on their ability to transfect mammalian cells is probed. Polymer bottle brushes with grafts made from partially hydrolysed poly(2-ethyl-2-oxazoline) are used while varying the length of the polymer backbone as well as the degree of hydrolysis (cationic charge content). Polyplex formation is investigated via gel electrophoresis, dye-displacement and dynamic light scattering. Bottle brushes show a superior ability to complex pDNA when compared to linear copolymers. Also, nucleic acid release was found to be improved by a graft architecture. Polyplexes based on bottle brush copolymers showed an elongated shape in transmission electron microscopy images. The cytotoxicity against mammalian cells is drastically reduced when a graft architecture is used instead of linear copolymers. Moreover, the best-performing bottle brush copolymer showed a transfection ability comparable with that of linear poly(ethylenimine), the gold standard of polymeric transfection agents, which is used as positive control. In combination with their markedly lowered cytotoxicity, cationic bottle brush copolymers are therefore shown to be a highly promising class of gene delivery vectors.
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Affiliation(s)
- Thomas G Floyd
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| | - Ji-Inn Song
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| | - Alexia Hapeshi
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| | - Sophie Laroque
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| | - Matthias Hartlieb
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476, Potsdam, Germany.
- Fraunhofer Institute for Applied Polymer Research (IAP), Geiselbergstraße 69, Potsdam-Golm, Germany
| | - Sébastien Perrier
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
- Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
- Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
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9-Aminoacridine Inhibits Ribosome Biogenesis by Targeting Both Transcription and Processing of Ribosomal RNA. Int J Mol Sci 2022; 23:ijms23031260. [PMID: 35163183 PMCID: PMC8836032 DOI: 10.3390/ijms23031260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 12/13/2022] Open
Abstract
Aminoacridines, used for decades as antiseptic and antiparasitic agents, are prospective candidates for therapeutic repurposing and new drug development. Although the mechanisms behind their biological effects are not fully elucidated, they are most often attributed to the acridines’ ability to intercalate into DNA. Here, we characterized the effects of 9-aminoacridine (9AA) on pre-rRNA metabolism in cultured mammalian cells. Our results demonstrate that 9AA inhibits both transcription of the ribosomal RNA precursors (pre-rRNA) and processing of the already synthesized pre-rRNAs, thereby rapidly abolishing ribosome biogenesis. Using a fluorescent intercalator displacement assay, we further show that 9AA can bind to RNA in vitro, which likely contributes to its ability to inhibit post-transcriptional steps in pre-rRNA maturation. These findings extend the arsenal of small-molecule compounds that can be used to block ribosome biogenesis in mammalian cells and have implications for the pharmacological development of new ribosome biogenesis inhibitors.
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Del Mundo IMA, Cho EJ, Dalby KN, Vasquez KM. A 'light-up' intercalator displacement assay for detection of triplex DNA stabilizers. Chem Commun (Camb) 2020; 56:1996-1999. [PMID: 31960843 PMCID: PMC7323859 DOI: 10.1039/c9cc08817b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here, we developed a coralyne-based, 'light-up' intercalator displacement assay to identify molecular stabilizers of triplex DNA using a sequence from a chromosomal breakpoint hotspot in the human c-MYC oncogene. Its potential to identify triplex DNA ligands was demonstrated using BePI and doxorubicin. Identification of triplex-interacting ligands may allow the regulation of genetic instability in human genomes.
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Affiliation(s)
- Imee M A Del Mundo
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX, USA.
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Molecular Dynamics Simulation of Homo-DNA: The Role of Crystal Packing in Duplex Conformation. CRYSTALS 2019. [DOI: 10.3390/cryst9100532] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The (4′→6′)-linked DNA homolog 2′,3′-dideoxy-β-D-glucopyranosyl nucleic acid (dideoxy-glucose nucleic acid or homo-DNA) exhibits stable self-pairing of the Watson–Crick and reverse-Hoogsteen types, but does not cross-pair with DNA. Molecular modeling and NMR solution studies of homo-DNA duplexes pointed to a conformation that was nearly devoid of a twist and a stacking distance in excess of 4.5 Å. By contrast, the crystal structure of the homo-DNA octamer dd(CGAATTCG) revealed a right-handed duplex with average values for helical twist and rise of ca. 15° and 3.8 Å, respectively. Other key features of the structure were strongly inclined base-pair and backbone axes in the duplex with concomitant base-pair slide and cross-strand stacking, and the formation of a dimer across a crystallographic dyad with inter-duplex base swapping. To investigate the conformational flexibility of the homo-DNA duplex and a potential influence of lattice interactions on its geometry, we used molecular dynamics (MD) simulations of the crystallographically observed dimer of duplexes and an isolated duplex in the solution state. The dimer of duplexes showed limited conformational flexibility, and key parameters such as helical rise, twist, and base-pair slide exhibited only minor fluctuations. The single duplex was clearly more flexible by comparison and underwent partial unwinding, albeit without significant lengthening. Thus, base stacking was preserved in the isolated duplex and two adenosines extruded from the stack in the dimer of duplexes were reinserted into the duplex and pair with Ts in a Hoogsteen mode. Our results confirmed that efficient stacking in homo-DNA seen in the crystal structure of a dimer of duplexes was maintained in the separate duplex. Therefore, lattice interactions did not account for the different geometries of the homo-DNA duplex in the crystal and earlier models that resembled inclined ladders with large base-pair separations that precluded efficient stacking.
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Marzo T, Cirri D, Ciofi L, Gabbiani C, Feis A, Di Pasquale N, Stefanini M, Biver T, Messori L. Synthesis, characterization and DNA interactions of [Pt3(TPymT)Cl3], the trinuclear platinum(II) complex of the TPymT ligand. J Inorg Biochem 2018; 183:101-106. [DOI: 10.1016/j.jinorgbio.2018.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 11/26/2022]
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8
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del Villar-Guerra R, Gray RD, Trent JO, Chaires JB. A rapid fluorescent indicator displacement assay and principal component/cluster data analysis for determination of ligand-nucleic acid structural selectivity. Nucleic Acids Res 2018; 46:e41. [PMID: 29361140 PMCID: PMC6283418 DOI: 10.1093/nar/gky019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/12/2017] [Accepted: 01/09/2018] [Indexed: 12/23/2022] Open
Abstract
We describe a rapid fluorescence indicator displacement assay (R-FID) to evaluate the affinity and the selectivity of compounds binding to different DNA structures. We validated the assay using a library of 30 well-known nucleic acid binders containing a variety chemical scaffolds. We used a combination of principal component analysis and hierarchical clustering analysis to interpret the results obtained. This analysis classified compounds based on selectivity for AT-rich, GC-rich and G4 structures. We used the FID assay as a secondary screen to test the binding selectivity of an additional 20 compounds selected from the NCI Diversity Set III library that were identified as G4 binders using a thermal shift assay. The results showed G4 binding selectivity for only a few of the 20 compounds. Overall, we show that this R-FID assay, coupled with PCA and HCA, provides a useful tool for the discovery of ligands selective for particular nucleic acid structures.
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Affiliation(s)
- Rafael del Villar-Guerra
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Robert D Gray
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - John O Trent
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Jonathan B Chaires
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
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9
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Emanuele AA, Garcia GA. Mechanism of Action and Initial, In Vitro SAR of an Inhibitor of the Shigella flexneri Virulence Regulator VirF. PLoS One 2015; 10:e0137410. [PMID: 26352269 PMCID: PMC4564171 DOI: 10.1371/journal.pone.0137410] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 08/17/2015] [Indexed: 12/19/2022] Open
Abstract
Shigella spp. are among the main causative agents of acute diarrheal illness and claim more than 1 million lives per year worldwide. There are multiple bacterial genes that control the pathogenesis of Shigella, but the virF gene may be the most important. This gene, located on the primary pathogenicity island of Shigella, encodes VirF, an AraC-family transcriptional activator that is responsible for initiating the pathogenesis cycle in Shigella. We have previously shown that it is possible to attenuate the virulence of Shigella flexneri via small molecule inhibition of VirF. In this study, we probed the mechanism of action of our small molecule inhibitors of VirF. To enable these studies, we have developed a homologous and efficient expression and purification system for VirF and have optimized two different in vitro VirF-DNA binding assays. We have determined that one of our HTS hit compounds inhibits VirF binding to DNA with a calculated Ki similar to the effective doses seen in our transcriptional activation and virulence screens. This is consistent with inhibition of DNA binding as the mechanism of action of this hit compound. We have also screened 15 commercially sourced analogs of this compound and deduced an initial SAR from the approximately 100-fold range in activities. Our four other HTS hit compounds do not inhibit DNA binding and yet they do block VirF activity. This suggests that multiple agents with different molecular mechanisms of inhibition of VirF could be developed. Pursuing hits with different mechanisms of action could be a powerful approach to enhance activity and to circumvent resistance that could develop to any one of these agents.
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Affiliation(s)
- Anthony A. Emanuele
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States of America
| | - George A. Garcia
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States of America
- * E-mail:
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Hegde M, Sharath Kumar KS, Thomas E, Ananda H, Raghavan SC, Rangappa KS. A novel benzimidazole derivative binds to the DNA minor groove and induces apoptosis in leukemic cells. RSC Adv 2015. [DOI: 10.1039/c5ra16605e] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In the present study, we have synthesized various benzimidazole derivatives, evaluated their potential to act as DNA minor groove binder and tested their chemotherapeutic efficacy.
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Affiliation(s)
- Mahesh Hegde
- Department of Studies in Chemistry
- Manasagangotri, University of Mysore
- Mysuru-570006, India
| | | | - Elizabeth Thomas
- Department of Biochemistry
- Indian Institute of Science
- Bangalore-560012, India
| | - Hanumappa Ananda
- Department of Studies in Chemistry
- Manasagangotri, University of Mysore
- Mysuru-570006, India
| | - Sathees C. Raghavan
- Department of Biochemistry
- Indian Institute of Science
- Bangalore-560012, India
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Liu YP, Chen HL, Tzeng CC, Lu PJ, Lo CW, Lee YC, Tseng CH, Chen YL, Yang CN. TCH-1030 targeting on topoisomerase I induces S-phase arrest, DNA fragmentation, and cell death of breast cancer cells. Breast Cancer Res Treat 2013; 138:383-93. [PMID: 23430225 DOI: 10.1007/s10549-013-2441-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 01/31/2013] [Indexed: 11/29/2022]
Abstract
Camptothecin (CPT) and its derivatives are powerful anticancer agents, but these compounds are chemically unstable due to their α-hydroxy lactone six-membered E-ring structure, which is essential for trapping topoisomerase I (topo I)-DNA cleavage complexes. Moreover, the reversibility of trapping the topo I-DNA cleavage complex and the tight binding of CPTs to human serum albumin limit the levels of available active drug. CPT analogs are the only clinically available drugs that target topo I. Owing to the clinical importance of CPT analogs, the development of new anticancer agents which inhibit topo I is urgently needed. In the present study, we report the synthesis, biologic evaluation, and molecular mechanism of a series of substituted indeno[1,2-c]quinoline derivatives against the growth of several human cancer cell lines. We found that 9-methoxy-6-(piperazin-1-yl)-11H-indeno[1,2-c]quinoline-11-one O-3-(dimethylamino)propyl oxime (TCH-1030) intercalated into DNA and preferentially inhibited DNA topo I relaxation. Flow cytometric analysis and BrdU incorporation assays indicate that TCH-1030 alters cell cycle progression, induces S-phase arrest, and causes DNA polyploidy (>4 N) that is distinct from the typical G2-M arrest reported with known topoisomerase toxins. Our data indicate that TCH-1030 induces caspase 3 activation, PARP cleavage, γ-H2AX phosphorylation, and, consequently, DNA fragmentation and apoptosis. We also demonstrated that treatment with TCH-1030 significantly inhibits tumor growth in a BT483-xenograft nude mouse model. Taken together, we conclude that the primary mechanism of action of TCH-1030-induced cell cycle retardation and apoptosis-mediated DNA damage involves DNA binding and intercalation as well as topo I inhibition.
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Affiliation(s)
- Yu-Peng Liu
- Institute of Clinical Medicine, National Cheng Kung University, Medical College, Tainan, Taiwan
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