1
|
Lee JH, Shores KL, Breithaupt JJ, Lee CS, Fodera DM, Kwon JB, Ettyreddy AR, Myers KM, Evison BJ, Suchowerska AK, Gersbach CA, Leong KW, Truskey GA. PCSK9 activation promotes early atherosclerosis in a vascular microphysiological system. APL Bioeng 2023; 7:046103. [PMID: 37854060 PMCID: PMC10581720 DOI: 10.1063/5.0167440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/27/2023] [Indexed: 10/20/2023] Open
Abstract
Atherosclerosis is a primary precursor of cardiovascular disease (CVD), the leading cause of death worldwide. While proprotein convertase subtilisin/kexin 9 (PCSK9) contributes to CVD by degrading low-density lipoprotein receptors (LDLR) and altering lipid metabolism, PCSK9 also influences vascular inflammation, further promoting atherosclerosis. Here, we utilized a vascular microphysiological system to test the effect of PCSK9 activation or repression on the initiation of atherosclerosis and to screen the efficacy of a small molecule PCSK9 inhibitor. We have generated PCSK9 over-expressed (P+) or repressed (P-) human induced pluripotent stem cells (iPSCs) and further differentiated them to smooth muscle cells (viSMCs) or endothelial cells (viECs). Tissue-engineered blood vessels (TEBVs) made from P+ viSMCs and viECs resulted in increased monocyte adhesion compared to the wild type (WT) or P- equivalents when treated with enzyme-modified LDL (eLDL) and TNF-α. We also found significant viEC dysfunction, such as increased secretion of VCAM-1, TNF-α, and IL-6, in P+ viECs treated with eLDL and TNF-α. A small molecule compound, NYX-1492, that was originally designed to block PCSK9 binding with the LDLR was tested in TEBVs to determine its effect on lowering PCSK9-induced inflammation. The compound reduced monocyte adhesion in P+ TEBVs with evidence of lowering secretion of VCAM-1 and TNF-α. These results suggest that PCSK9 inhibition may decrease vascular inflammation in addition to lowering plasma LDL levels, enhancing its anti-atherosclerotic effects, particularly in patients with elevated chronic inflammation.
Collapse
Affiliation(s)
- Jounghyun H. Lee
- Department of Biomedical Engineering, Columbia University, New York, New York 10032, USA
| | - Kevin L. Shores
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Jason J. Breithaupt
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Caleb S. Lee
- Department of Biomedical Engineering, Columbia University, New York, New York 10032, USA
| | - Daniella M. Fodera
- Department of Biomedical Engineering, Columbia University, New York, New York 10032, USA
| | | | | | - Kristin M. Myers
- Department of Mechanical Engineering, Columbia University, New York, New York 10032, USA
| | | | | | | | - Kam W. Leong
- Department of Biomedical Engineering, Columbia University, New York, New York 10032, USA
| | - George A. Truskey
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| |
Collapse
|
2
|
Mansour OC, Nudelman A, Rephaeli A, Phillips DR, Cutts SM, Evison BJ. An evaluation of the interaction of pixantrone with formaldehyde-releasing drugs in cancer cells. Cancer Chemother Pharmacol 2022; 89:773-784. [PMID: 35460360 DOI: 10.1007/s00280-022-04435-1] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 04/02/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE Pixantrone is a synthetic aza-anthracenedione currently used in the treatment of non-Hodgkin's lymphoma. The drug is firmly established as a poison of the nuclear enzyme topoisomerase II, however, pixantrone can also generate covalent drug-DNA adducts following activation by formaldehyde. While pixantrone-DNA adducts form proficiently in vitro, little evidence is presently at hand to indicate their existence within cells. The molecular nature of these lesions within cancer cells exposed to pixantrone and formaldehyde-releasing prodrugs was characterized along with the cellular responses to their formation. METHODS In vitro crosslinking assays, [14C] scintillation counting analyses and alkaline comet assays were applied to characterize pixantrone-DNA adducts. Flow cytometry, cell growth inhibition and clonogenic assays were used to measure cancer cell kill and survival. RESULTS Pixantrone-DNA adducts were not detectable in MCF-7 breast cancer cells exposed to [14C] pixantrone (10-40 µM) alone, however the addition of the formaldehyde-releasing prodrug AN9 yielded readily measurable levels of the lesion at ~ 1 adduct per 10 kb of genomic DNA. Co-administration with AN9 completely reversed topoisomerase II-associated DNA damage induction by pixantrone yet potentiated cell kill by the drug, suggesting that pixantrone-DNA adducts may promote a topoisomerase II-independent mechanism of cell death. Pixantrone-DNA adduct-forming treatments generally conferred mild synergism in multiple cell lines in various cell death and clonogenic assays, while pixantrone analogues either incapable or relatively defective in forming DNA adducts demonstrated antagonism when combined with AN9. CONCLUSIONS The features unique to pixantrone-DNA adducts may be leveraged to enhance cancer cell kill and may be used to guide the design of pixantrone analogues that generate adducts with more favorable anticancer properties.
Collapse
Affiliation(s)
- Oula C Mansour
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Abraham Nudelman
- Chemistry Department, Bar-Ilan University, 52900, Ramat-Gan, Israel
| | - Ada Rephaeli
- Sackler Faculty of Medicine, Felsenstein Medical Research Center, Tel-Aviv University, 49100, Petach-Tikva, Israel
| | - Don R Phillips
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Suzanne M Cutts
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| | - Benny J Evison
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
- Nyrada Inc, Suite 2, Level 3, 828 Pacific Highway, Gordon, NSW, 2072, Australia.
| |
Collapse
|
3
|
Medan J, Sleebs BE, Lackovic K, Watson KG, Evison BJ, Phillips DR, Cutts SM. Development of an automated assay for accelerated in vitro detection of DNA adduct-inducing and crosslinking agents. Bioorg Med Chem Lett 2021; 35:127813. [PMID: 33486050 DOI: 10.1016/j.bmcl.2021.127813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 10/08/2020] [Revised: 12/21/2020] [Accepted: 01/17/2021] [Indexed: 10/22/2022]
Abstract
Current techniques for the identification of DNA adduct-inducing and DNA interstrand crosslinking agents include electrophoretic crosslinking assays, electrophoretic gel shift assays, DNA and RNA stop assays, mass spectrometry-based methods and 32P-post-labelling. While these assays provide considerable insight into the site and stability of the interaction, they are relatively expensive, time-consuming and sometimes rely on the use of radioactively-labelled components, and thus are ill-suited to screening large numbers of compounds. A novel medium throughput assay was developed to overcome these limitations and was based on the attachment of a biotin-tagged double stranded (ds) oligonucleotide to Corning DNA-Bind plates. We aimed to detect anthracycline and anthracenedione DNA adducts which form by initial non-covalent intercalation with duplex DNA, and subsequent covalent adduct formation which is mediated by formaldehyde. Following drug treatment, DNA samples were subjected to a denaturation step, washing and then measurement by fluorescence to detect remaining drug-DNA species using streptavidin-europium. This dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA) is a time-resolved fluorescence intensity assay where the fluorescence signal arises only from stabilised drug-DNA complexes. We applied this new methodology to the identification of anthracycline-like compounds with the ability to functionally crosslink double-strand oligonucleotides. The entire procedure can be performed by robotics, requiring low volumes of compounds and reagents, thereby reducing costs and enabling multiple compounds to be assessed on a single microtitre plate.
Collapse
Affiliation(s)
- Jelena Medan
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia; Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kurt Lackovic
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia; Cancer Trials Australia, Melbourne, Victoria 3000, Australia
| | - Keith G Watson
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia
| | - Benny J Evison
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia; Nyrada Inc, 828 Pacific Highway, Gordon, NSW 2072, Australia
| | - Don R Phillips
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - Suzanne M Cutts
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia.
| |
Collapse
|
4
|
Pumuye PP, Evison BJ, Konda SK, Collins JG, Kelso C, Medan J, Sleebs BE, Watson K, Phillips DR, Cutts SM. Formaldehyde-activated WEHI-150 induces DNA interstrand crosslinks with unique structural features. Bioorg Med Chem 2020; 28:115260. [PMID: 31870833 DOI: 10.1016/j.bmc.2019.115260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/18/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 12/17/2022]
Abstract
Mitoxantrone is an anticancer anthracenedione that can be activated by formaldehyde to generate covalent drug-DNA adducts. Despite their covalent nature, these DNA lesions are relatively labile. It was recently established that analogues of mitoxantrone featuring extended side-chains terminating in primary amino groups typically yielded high levels of stable DNA adducts following their activation by formaldehyde. In this study we describe the DNA sequence-specific binding properties of the mitoxantrone analogue WEHI-150 which is the first anthracenedione to form apparent DNA crosslinks mediated by formaldehyde. The utility of this compound lies in the versatility of the covalent binding modes displayed. Unlike other anthracenediones described to date, WEHI-150 can mediate covalent adducts that are independent of interactions with the N-2 of guanine and is capable of adduct formation at novel DNA sequences. Moreover, these covalent adducts incorporate more than one formaldehyde-mediated bond with DNA, thus facilitating the formation of highly lethal DNA crosslinks. The versatility of binding observed is anticipated to allow the next generation of anthracenediones to interact with a broader spectrum of nucleic acid species than previously demonstrated by the parent compounds, thus allowing for more diverse biological activities.
Collapse
Affiliation(s)
- Paul P Pumuye
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - Benny J Evison
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - Shyam K Konda
- School of Science, University of New South Wales, Canberra 2610, Australia
| | - J Grant Collins
- School of Science, University of New South Wales, Canberra 2610, Australia
| | - Celine Kelso
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Jelena Medan
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia; Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Keith Watson
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia
| | - Don R Phillips
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - Suzanne M Cutts
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia.
| |
Collapse
|
5
|
Masarudin MJ, Cutts SM, Evison BJ, Phillips DR, Pigram PJ. Factors determining the stability, size distribution, and cellular accumulation of small, monodisperse chitosan nanoparticles as candidate vectors for anticancer drug delivery: application to the passive encapsulation of [(14)C]-doxorubicin. Nanotechnol Sci Appl 2015; 8:67-80. [PMID: 26715842 PMCID: PMC4686320 DOI: 10.2147/nsa.s91785] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [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] [Indexed: 01/12/2023] Open
Abstract
Development of parameters for the fabrication of nanosized vectors is pivotal for its successful administration in therapeutic applications. In this study, homogeneously distributed chitosan nanoparticles (CNPs) with diameters as small as 62 nm and a polydispersity index (PDI) of 0.15 were synthesized and purified using a simple, robust method that was highly reproducible. Nanoparticles were synthesized using modified ionic gelation of the chitosan polymer with sodium tripolyphosphate. Using this method, larger aggregates were mechanically isolated from single particles in the nanoparticle population by selective efficient centrifugation. The presence of disaggregated monodisperse nanoparticles was confirmed using atomic force microscopy. Factors such as anions, pH, and concentration were found to affect the size and stability of nanoparticles directly. The smallest nanoparticle population was ∼62 nm in hydrodynamic size, with a low PDI of 0.15, indicating high particle homogeneity. CNPs were highly stable and retained their monodisperse morphology in serum-supplemented media in cell culture conditions for up to 72 hours, before slowly degrading over 6 days. Cell viability assays demonstrated that cells remained viable following a 72-hour exposure to 1 mg/mL CNPs, suggesting that the nanoparticles are well tolerated and highly suited for biomedical applications. Cellular uptake studies using fluorescein isothiocyanate-labeled CNPs showed that cancer cells readily accumulate the nanoparticles 30 minutes posttreatment and that nanoparticles persisted within cells for up to 24 hours posttreatment. As a proof of principle for use in anticancer therapeutic applications, a [(14)C]-radiolabeled form of the anticancer agent doxorubicin was efficiently encapsulated within the CNP, confirming the feasibility of using this system as a drug delivery vector.
Collapse
Affiliation(s)
- Mas Jaffri Masarudin
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Suzanne M Cutts
- Department of Biochemistry, La Trobe University, Melbourne, Victoria, Australia
| | - Benny J Evison
- Department of Chemical Biology and Therapeutics, St Jude Children's Hospital, Memphis, TN, USA
| | - Don R Phillips
- Department of Biochemistry, La Trobe University, Melbourne, Victoria, Australia
| | - Paul J Pigram
- Department of Physics, La Trobe University, Melbourne, Victoria, Australia
| |
Collapse
|
6
|
Evison BJ, Sleebs BE, Watson KG, Phillips DR, Cutts SM. Mitoxantrone, More than Just Another Topoisomerase II Poison. Med Res Rev 2015; 36:248-99. [PMID: 26286294 DOI: 10.1002/med.21364] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [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: 11/12/2014] [Revised: 07/13/2015] [Accepted: 07/14/2015] [Indexed: 02/06/2023]
Abstract
Mitoxantrone is a synthetic anthracenedione originally developed to improve the therapeutic profile of the anthracyclines and is commonly applied in the treatment of breast and prostate cancers, lymphomas, and leukemias. A comprehensive overview of the drug's molecular, biochemical, and cellular pharmacology is presented here, beginning with the cardiotoxic nature of its predecessor doxorubicin and how these properties shaped the pharmacology of mitoxantrone itself. Although mitoxantrone is firmly established as a DNA topoisomerase II poison within mammalian cells, it is now clear that the drug interacts with a much broader range of biological macromolecules both covalently and noncovalently. Here, we consider each of these interactions in the context of their wider biological relevance to cancer therapy and highlight how they may be exploited to further enhance the therapeutic value of mitoxantrone. In doing so, it is now clear that mitoxantrone is more than just another topoisomerase II poison.
Collapse
Affiliation(s)
- Benny J Evison
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, 3086, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Keith G Watson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Don R Phillips
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, 3086, Australia
| | - Suzanne M Cutts
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, 3086, Australia
| |
Collapse
|
7
|
Ankers EA, Evison BJ, Phillips DR, Brownlee RTC, Cutts SM. Design, synthesis, and DNA sequence selectivity of formaldehyde-mediated DNA-adducts of the novel N-(4-aminobutyl) acridine-4-carboxamide. Bioorg Med Chem Lett 2014; 24:5710-5715. [PMID: 25453806 DOI: 10.1016/j.bmcl.2014.10.062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 09/08/2014] [Revised: 10/13/2014] [Accepted: 10/17/2014] [Indexed: 11/30/2022]
Abstract
A novel derivative of the anti-tumor agent N-[2-(dimethylamino)ethyl]acridine-4-carboxamide (DACA) was prepared by reduction of 9-oxoacridan-4-carboxylic acid to acridine-4-carboxylic acid with subsequent conversion to N-(4-aminobutyl)acridine-4-carboxamide (C4-DACA). Molecular modeling studies suggested that a DACA analogue comprising a side chain length of four carbons was optimal to form formaldehyde-mediated drug-DNA adducts via the minor groove. An in vitro transcription assay revealed that formaldehyde-mediated C4-DACA-DNA adducts selectively formed at CpG and CpA dinucleotide sequences, which is strikingly similar to that of formaldehyde-activated anthracenediones such as pixantrone.
Collapse
Affiliation(s)
- Elizabeth A Ankers
- Department of Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Bundoora 3086, Australia
| | - Benny J Evison
- Department of Biochemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Bundoora 3086, Australia; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Don R Phillips
- Department of Biochemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Bundoora 3086, Australia
| | - Robert T C Brownlee
- Department of Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Bundoora 3086, Australia
| | - Suzanne M Cutts
- Department of Biochemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Bundoora 3086, Australia.
| |
Collapse
|
8
|
Pumuye PP, Medan JE, Sleebs B, Watson K, Evison BJ, Phillips DR, Cutts SM. Abstract C279: Novel anthracenedione derivatives demonstrating several potential modes of actions. Mol Cancer Ther 2013. [DOI: 10.1158/1535-7163.targ-13-c279] [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
DNA has been regarded as the primary target of numerous non-specific cytotoxic anticancer agents such as the nitrogen mustards and anthracycline antibiotics. The anthracyclines, most notably doxorubicin, proved to be highly potent and were thus incorporated into numerous chemotherapeutic regimens. However, their dose dependent redox activity that presumably contributes to their broad spectrum versatility is also associated with potentially lethal cardiotoxic adverse effects and thus, inspired the development of synthetic analogues including the anthracenediones. Like the anthracylines, their structural frame constitutes the DNA intercalating anthraquinone chromophore with functional amino groups stabilizing its insertion via hydrogen bonds and Van der Waal interactions. This interaction poisons the topoisomerase II cleavable complex which induces widespread DNA strand breaks culminating in the induction of apoptosis.
We have shown that the availability of the methyl donating molecule, formaldehyde, generates adduct formation via a covalent aminal linkage between the exocyclic N2 amino group of guanine residue at specific CpG dinucleotides and an amino group on the anthracenediones side chains. The formaldehyde mediated DNA adduct formation, achievable via simultaneous formaldehyde-releasing prodrug administration, increases cancer cell toxicity and potentially endows general cardioprotective activity. Such cardioprotection has been associated with formaldehyde-mediated doxorubicin-DNA adducts
We have synthesised a new series of anthracenediones that vary in their potential to induce covalent DNA adducts. We now show that the new anthracenediones including pixantrone (unlike the anthracyclines) also exhibits a preference for forming adducts with single stranded DNA and RNA, and these have similar characteristics to adducts that are formed with DNA.
Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C279.
Citation Format: Paul P. Pumuye, Jelena E. Medan, Brad Sleebs, Keith Watson, Benny J. Evison, Donald R. Phillips, Suzanne M. Cutts. Novel anthracenedione derivatives demonstrating several potential modes of actions. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C279.
Collapse
Affiliation(s)
| | | | - Brad Sleebs
- 2Walter and Eliza Hall Institute, Melbourne, Australia
| | - Keith Watson
- 2Walter and Eliza Hall Institute, Melbourne, Australia
| | | | | | | |
Collapse
|
9
|
Evison BJ, Pastuovic M, Bilardi RA, Forrest RA, Pumuye PP, Sleebs BE, Watson KG, Phillips DR, Cutts SM. M2, a novel anthracenedione, elicits a potent DNA damage response that can be subverted through checkpoint kinase inhibition to generate mitotic catastrophe. Biochem Pharmacol 2011; 82:1604-18. [DOI: 10.1016/j.bcp.2011.08.013] [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] [Received: 06/23/2011] [Revised: 08/10/2011] [Accepted: 08/11/2011] [Indexed: 12/01/2022]
|
10
|
Mansour OC, Evison BJ, Sleebs BE, Watson KG, Nudelman A, Rephaeli A, Buck DP, Collins JG, Bilardi RA, Phillips DR, Cutts SM. New anthracenedione derivatives with improved biological activity by virtue of stable drug-DNA adduct formation. J Med Chem 2010; 53:6851-66. [PMID: 20860366 DOI: 10.1021/jm901894c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mitoxantrone is an anticancer agent that acts as a topoisomerase II poison, however, it can also be activated by formaldehyde to form DNA adducts. Pixantrone, a 2-aza-anthracenedione with terminal primary amino groups in its side chains, forms formaldehyde-mediated adducts with DNA more efficiently than mitoxantrone. Molecular modeling studies indicated that extension of the "linker" region of anthracenedione side arms would allow the terminal primary amino greater flexibility and thus access to the guanine residues on the opposite DNA strand. New derivatives based on the pixantrone and mitoxantrone backbones were synthesized, and these incorporated primary amino groups as well as extended side chains. The stability of DNA adducts increased with increasing side chain length of the derivatives. A mitoxantrone derivative bearing extended side chains (7) formed the most stable adducts with ∼100-fold enhanced stability compared to mitoxantrone. This finding is of great interest because long-lived drug-DNA adducts are expected to perturb DNA-dependent functions at all stages of the cell cycle.
Collapse
Affiliation(s)
- Oula C Mansour
- Department of Biochemistry, La Trobe University, Victoria 3086, Australia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
The binding of the anticancer drug pixantrone (6,9-bis[(2-aminoethyl)amino]benzo[g]isoquinoline-5,10-dione dimaleate) to the octanucleotide duplexes d(ACGATCGT)(2) and the corresponding C-5 methylated cytosine ((5Me)C) analogue d(A(5Me)CGAT(5Me)CGT)(2) has been studied by NMR spectroscopy and molecular modelling. The large upfield shifts observed for the resonances from the aromatic protons of pixantrone upon addition to either d(ACGATCGT)(2) or the corresponding (5Me)C analogue is consistent with the drug binding the octanucleotides by intercalation. The selective reduction in the sequential NOEs between the C(2)-G(3) and C(6)-G(7) nucleotides in NOESY spectra of either octanucleotide with added pixantrone confirms the intercalative binding mechanism. Strong NOEs from the side-chain ethylene protons of pixantrone to the H5 protons and the 5-CH(3) protons of the C(2) and C(6) residues of d(ACGATCGT)(2) and d(A(5Me)CGAT(5Me)CGT)(2), respectively, indicate that pixantrone predominantly intercalates from the DNA major groove at the 5'-CG and 5'-(5Me)CG sites. Simple molecular models based on the conclusions from the NMR experiments indicated that the (5Me)C groups do not represent a steric barrier to intercalation from the major groove. However, the observation of weak NOEs from the ethylene protons of pixantrone to a variety of minor groove protons from either octanucleotide suggests that the drug can also associate in the minor groove.
Collapse
Affiliation(s)
- Najia Adnan
- School of Physical, Environmental and Mathematical Sciences University College, University of New South Wales, Australian Defence Force Academy, Northcott Drive, Campbell, ACT 2600, Australia
| | | | | | | | | | | |
Collapse
|
12
|
Evison BJ, Mansour OC, Sleebs BE, Watson KG, Rephaeli A, Nudelman A, Phillips DR, Cutts SM. Abstract 3507: Facilitating pixantrone-induced DNA damage and subsequent cell kill through formaldehyde activation and improvements in drug design. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-3507] [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
Pixantrone is a novel aza-anthracenedione originally developed to improve the therapeutic profile of mitoxantrone, a DNA-interactive agent currently used in the clinical management of a range of haematological malignancies and solid tumours. Like mitoxantrone, pixantrone interacts with DNA via intercalation and stimulates topoisomerase II-mediated DNA cleavage, presumably by stabilising the cleavable complex. Despite the drug's ability to stimulate DNA cleavage via topoisomerase II impairment, this form of DNA damage does not directly correlate with drug cytotoxicity, suggesting that pixantrone may be operating by a distinct, currently undefined mechanism of cell kill. A novel form of pixantrone-DNA interaction has recently emerged in which the drug can be efficiently activated by formaldehyde to yield covalent drug-DNA adducts. In cellular systems, pixantrone exhibits a mild synergistic relationship with the formaldehyde-releasing prodrug AN-9, indicating a favourable role for formaldehyde in mediating pixantrone-induced cell kill. A variety of methods including in vitro transcription and mass spectrometry have established that formaldehyde-activated pixantrone is a monofunctional DNA alkylator that binds selectively to CpG and CpA dinucleotides via the exocyclic N2 amino group of guanine within DNA. Crucially, formaldehyde provides the methylene bridge that covalently links DNA with a single drug side-chain. A major functional limitation of the monoadduct is its poor intrinsic stability (t1/2 = 75 min). It was subsequently rationalised that an increase in drug side-chain length may permit the drug to completely bridge the two strands of duplex DNA, much like an interstrand crosslink. Accordingly, new anthracenediones were synthesised that incorporated symmetrical side chains of the nature -NH-(CH2)n-NH2 (where n = 2—5). An in vitro crosslinking assay demonstrated that side-chain extension generally conferred a remarkable increase in the temporal stability of formaldehyde-activated anthracenedione-DNA adducts. A clear and direct relationship existed between side-chain length and drug-DNA adduct half-life with MX5 (n = 5) exhibiting exceptional stability (t1/2 > 2 days). Significantly, the enhanced drug-DNA adduct stability was reflected in breast adenocarcinoma MCF-7 cells where derivatives with longer side-chains were synergistic in combination with the formaldehyde-releasing prodrug AN-9.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3507.
Collapse
|
13
|
Abstract
A major class of anticancer agents in current clinical use exerts its anticancer effects by binding covalently or non-covalently to DNA. A detailed understanding of the nature of these drug-DNA complexes would be expected to lead to better uses of these drugs, and also assist with the design of improved drug derivatives. Here, we present a transcriptional footprinting assay that can be implemented to define the DNA sequence specificity and kinetics associated with drug-DNA complexes. The basic steps involve the formation of drug-DNA complexes, the formation of synchronised initiated transcripts, and finally transcriptional elongation to reveal drug blockage sites that impede the progression of RNA polymerase. We have used the "in vitro transcription assay" to investigate many covalent drug-DNA interactions; most notably those obtained using anthracycline anticancer agents such as doxorubicin and anthracenedione-based anticancer agents, including mitoxantrone and pixantrone.
Collapse
Affiliation(s)
- Benny J Evison
- Department of Biochemistry, La Trobe University, Bundoora, VIC, Australia
| | | | | |
Collapse
|
14
|
Evison BJ, Bilardi RA, Chiu FCK, Pezzoni G, Phillips DR, Cutts SM. CpG methylation potentiates pixantrone and doxorubicin-induced DNA damage and is a marker of drug sensitivity. Nucleic Acids Res 2009; 37:6355-70. [PMID: 19720735 PMCID: PMC2770666 DOI: 10.1093/nar/gkp700] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [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: 12/13/2022] Open
Abstract
DNA methylation is an epigenetic modification of the mammalian genome that occurs predominantly at cytosine residues of the CpG dinucleotide. Following formaldehyde activation, pixantrone alkylates DNA and particularly favours the CpG motif. Aberrations in CpG methylation patterns are a feature of most cancer types, a characteristic that may determine their susceptibility to specific drug treatments. Given their common target, DNA methylation may modulate the DNA damage induced by formaldehyde-activated pixantrone. In vitro transcription, mass spectrometry and oligonucleotide band shift assays were utilized to establish that pixantrone–DNA adduct formation was consistently enhanced 2–5-fold at discrete methylated CpG doublets. The methylation-mediated enhancement was exquisitely sensitive to the position of the methyl substituent since methylation at neighboring cytosine residues failed to confer an increase in pixantrone–DNA alkylation. Covalent modification of DNA by formaldehyde-activated doxorubicin, but not cisplatin, was augmented by neighbouring CpG methylation, indicating that modulation of binding by CpG methylation is not a general feature of all alkylators. HCT116 colon cancer cells vastly deficient in CpG methylation were 12- and 10-fold more resistant to pixantrone and doxorubicin relative to the wild-type line, suggesting that these drugs may selectively recognize the aberrant CpG methylation profiles characteristic of most tumour types.
Collapse
Affiliation(s)
- Benny J Evison
- Department of Biochemistry, La Trobe University, Victoria 3086
| | | | | | | | | | | |
Collapse
|
15
|
Evison BJ, Chiu F, Pezzoni G, Phillips DR, Cutts SM. Formaldehyde-activated Pixantrone is a monofunctional DNA alkylator that binds selectively to CpG and CpA doublets. Mol Pharmacol 2008; 74:184-94. [PMID: 18413664 DOI: 10.1124/mol.108.045625] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The topoisomerase II poison mitoxantrone is important in the clinical management of human malignancies. Pixantrone, a novel aza-anthracenedione developed to improve the therapeutic profile of mitoxantrone, can efficiently alkylate DNA after formaldehyde activation. In vitro transcriptional analysis has now established that formaldehyde-activated pixantrone generates covalent adducts selectively at discrete CpG or CpA dinucleotides, suggesting that the activated complex binds to guanine or cytosine (or both) bases. The stability of pixantrone adduct-induced transcriptional blockages varied considerably, reflecting a mixture of distinct pixantrone adduct types that may include relatively labile monoadducts and more stable interstrand cross-links. 6,9-Bis-[[2-(dimethylamino)ethyl]amino]benzo[g]isoquinoline-5,10-dione (BBR 2378), the dimethyl N-substituted analog of pixantrone, could not form adducts, suggesting that pixantrone alkylates DNA through the primary amino functions located in each side chain of the drug. Pixantrone generated DNA adducts only when guanine was present in substrates and exhibited a lack of adduct formation with inosine-containing polynucleotides, confirming that the N2 amino group of guanine is the site for covalent attachment of the drug. Mass spectrometric analysis of oligonucleotide-drug complexes confirmed that formation of covalent pixantrone-DNA adducts is mediated by a single methylene linkage provided by formaldehyde and that this occurs only with guanine-containing double stranded oligonucleotide substrates. CpG methylation, an epigenetic modification of the mammalian genome, significantly enhanced the generation of pixantrone-DNA adducts within a methylated DNA substrate, indicating that the methylated dinucleotide may be a favored target in a cellular environment.
Collapse
Affiliation(s)
- Benny J Evison
- Department of Biochemistry, La Trobe University, Victoria 3086, Australia
| | | | | | | | | |
Collapse
|