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Coverdale JPC, Kostrhunova H, Markova L, Song H, Postings M, Bridgewater HE, Brabec V, Rogers NJ, Scott P. Triplex metallohelices have enantiomer-dependent mechanisms of action in colon cancer cells. Dalton Trans 2023; 52:6656-6667. [PMID: 37114730 DOI: 10.1039/d3dt00948c] [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: 04/29/2023]
Abstract
Self-assembled enantiomers of an asymmetric di-iron metallohelix differ in their antiproliferative activities against HCT116 colon cancer cells such that the compound with Λ-helicity at the metals becomes more potent than the Δ compound with increasing exposure time. From concentration- and temperature-dependent 57Fe isotopic labelling studies of cellular accumulation we postulate that while the more potent Λ enantiomer undergoes carrier-mediated efflux, for Δ the process is principally equilibrative. Cell fractionation studies demonstrate that both enantiomers localise in a similar fashion; compound is observed mostly within the cytoskeleton and/or genomic DNA, with significant amounts also found in the nucleus and membrane, but with negligible concentration in the cytosol. Cell cycle analyses using flow cytometry reveal that the Δ enantiomer induces mild arrest in the G1 phase, while Λ causes a very large dose-dependent increase in the G2/M population at a concentration significantly below the relevant IC50. Correspondingly, G2-M checkpoint failure as a result of Λ-metallohelix binding to DNA is shown to be feasible by linear dichroism studies, which indicate, in contrast to the Δ compound, a quite specific mode of binding, probably in the major groove. Further, spindle assembly checkpoint (SAC) failure, which could also be responsible for the observed G2/M arrest, is established as a feasible mechanism for the Λ helix via drug combination (synergy) studies and the discovery of tubulin and actin inhibition. Here, while the Λ compound stabilizes F-actin and induces a distinct change in tubulin architecture of HCT116 cells, Δ promotes depolymerization and more subtle changes in microtubule and actin networks.
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Affiliation(s)
- J P C Coverdale
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- School of Pharmacy, Institute of Clinical Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - H Kostrhunova
- The Czech Academy of Sciences, Institute of Biophysics, Kralovopolska 135, CZ-61265 Brno, Czech Republic
| | - L Markova
- The Czech Academy of Sciences, Institute of Biophysics, Kralovopolska 135, CZ-61265 Brno, Czech Republic
| | - H Song
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- Beijing Area Major Laboratory of Peptide and Small Molecular Drugs, School of Pharmaceutical Sciences, Capital Medical University, Beijing, 100069, China
| | - M Postings
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - H E Bridgewater
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
- Centre of Exercise, Sport and Life Science, Faculty of Health and Life Sciences, Coventry University, Coventry, CV1 5FB, UK
| | - V Brabec
- The Czech Academy of Sciences, Institute of Biophysics, Kralovopolska 135, CZ-61265 Brno, Czech Republic
| | - N J Rogers
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - P Scott
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
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Khattib D, Ishan M, Karmakar S, Kostrhunova H, Brabec V, Gibson D. Oxidation of cis-Diamminediacetato Pt II with Hydrogen Peroxide Can Give Rise to Two Isomeric Pt IV Products. Chemistry 2020; 26:9475-9480. [PMID: 32428256 DOI: 10.1002/chem.202001472] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/08/2020] [Indexed: 11/12/2022]
Abstract
The oxidation of cis-[Pt(NH3 )2 (OAc)2 ] with H2 O2 yields a mixture of two isomers: ctc-[Pt(NH3 )2 (OH)2 (OAc)2 ] and ctc-[Pt(NH3 )2 (OH)(OAc)(OH)(OAc)]. Following modification with 4-phenylbutyric (PhB) anhydride, two isomers were separated and characterized; the symmetric ctc-[Pt(NH3 )2 (PhB)2 (OAc)2 ] (1) and the nonsymmetric ctc-[Pt(NH3 )2 (PhB)(OAc)(PhB)(OAc)] (2). They differ in their log P values and despite having similar cellular uptake and similar DNA platination levels, the symmetric ctc-[Pt(NH3 )2 (OH)2 (OAc)2 ] is more than 4-fold more potent than the nonsymmetric isomer in a panel of 4 cancer cell lines.
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Affiliation(s)
- D Khattib
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
| | - M Ishan
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
| | - S Karmakar
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
| | - H Kostrhunova
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
| | - V Brabec
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
| | - D Gibson
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
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Abstract
The requirement for novel platinum antitumor drugs led to the concept of synthesis of novel platinum drugs based on targeting cisplatin to various carrier molecules. We have shown [Loskotova, H., and Brabec, V. (1999) Eur. J. Biochem. 266, 392-402] that attachment of DNA minor-groove-binder distamycin to cisplatin changes several features of DNA-binding mode of the parent platinum drug. Major differences comprise different conformational changes in DNA and a considerably higher interstrand cross-linking efficiency. The studies of the present work have been directed to the analysis of oligodeoxyribonucleotide duplexes containing single, site-specific adducts of platinum-distamycin conjugates. These uniquely modified duplexes were analyzed by Maxam-Gilbert footprinting, phase-sensitive gel electrophoresis bending assay and chemical probes of DNA conformation. The results have indicated that the attachment of distamycin to cisplatin mainly affects the sites involved in the interstrand cross-links so that these adducts are preferentially formed between complementary guanine and cytosine residues. This interstrand cross-link bends the helix axis by approximately 35 degrees toward minor groove, unwinds DNA by approximately 95 degrees and distorts DNA symmetrically around the adduct. In addition, CD spectra of restriction fragments modified by the cisplatin-distamycin conjugates have demonstrated that distamycin moiety in the interstrand cross-links of these compounds interacts with DNA. This interaction facilitates the formation of these adducts. Hence, the structural impact of the specific interstrand cross-link detected in this study deserves attention when biological behavior of cisplatin derivatives targeted by oligopeptide DNA minor-groove-binders is evaluated.
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Affiliation(s)
- H Kostrhunova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-61265 Brno, Czech Republic
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