1
|
Sun Y, Sun P, Li Z, Qu L, Guo W. Natural flavylium-inspired far-red to NIR-II dyes and their applications as fluorescent probes for biomedical sensing. Chem Soc Rev 2022; 51:7170-7205. [PMID: 35866752 DOI: 10.1039/d2cs00179a] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fluorescent probes that emit in the far-red (600-700 nm), first near-infrared (NIR-I, 700-900 nm), and second NIR (NIR-II, 900-1700 nm) regions possess unique advantages, including low photodamage and deep penetration into biological samples. Notably, NIR-II optical imaging can achieve tissue penetration as deep as 5-20 mm, which is critical for biomedical sensing and clinical applications. Much research has focused on developing far-red to NIR-II dyes to meet the needs of modern biomedicine. Flavylium compounds are natural colorants found in many flowers and fruits. Flavylium-inspired dyes are ideal platforms for constructing fluorescent probes because of their far-red to NIR emissions, high quantum yields, high molar extinction coefficients, and good water solubilities. The synthetic and structural diversities of flavylium dyes also enable NIR-II probe development, which markedly advance the field of NIR-II in vivo imaging. In the last decade, there have been huge developments in flavylium-inspired dyes and their applications as far-red to NIR fluorescent probes for biomedical applications. In this review, we highlight the optical properties of representative flavylium dyes, design strategies, sensing mechanisms, and applications as fluorescent probes for detecting and visualizing important biomedical species and events. This review will prompt further research not only on flavylium dyes, but also into all far-red to NIR fluorophores and fluorescent probes. Moreover, this interest will hopefully spillover into applications related to complex biological systems and clinical treatments, ranging in focus from the sub-organelle to whole-animal levels.
Collapse
Affiliation(s)
- Yuanqiang Sun
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
| | - Pengjuan Sun
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
| | - Zhaohui Li
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
| | - Lingbo Qu
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
| | - Wei Guo
- School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| |
Collapse
|
2
|
Singleton DC, Mowday AM, Guise CP, Syddall SP, Bai SY, Li D, Ashoorzadeh A, Smaill JB, Wilson WR, Patterson AV. Bioreductive prodrug PR-104 improves the tumour distribution and titre of the nitroreductase-armed oncolytic adenovirus ONYX-411 NTR leading to therapeutic benefit. Cancer Gene Ther 2022; 29:1021-1032. [PMID: 34837065 DOI: 10.1038/s41417-021-00409-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/05/2021] [Accepted: 11/09/2021] [Indexed: 11/09/2022]
Abstract
Advances in the field of cancer immunotherapy have stimulated renewed interest in adenoviruses as oncolytic agents. Clinical experience has shown that oncolytic adenoviruses are safe and well tolerated but possess modest single-agent activity. One approach to improve the potency of oncolytic viruses is to utilise their tumour selectivity to deliver genes encoding prodrug-activating enzymes. These enzymes can convert prodrugs into cytotoxic species within the tumour; however, these cytotoxins can interfere with viral replication and limit utility. In this work, we evaluated the activity of a nitroreductase (NTR)-armed oncolytic adenovirus ONYX-411NTR in combination with the clinically tested bioreductive prodrug PR-104. Both NTR-expressing cells in vitro and xenografts containing a minor population of NTR-expressing cells were highly sensitive to PR-104. Pharmacologically relevant prodrug exposures did not interfere with ONYX-411NTR replication in vitro. In vivo, prodrug administration increased virus titre and improved virus distribution within tumour xenografts. Colonisation of tumours with high ONYX-411NTR titre resulted in NTR expression and prodrug activation. The combination of ONYX-411NTR with PR-104 was efficacious against HCT116 xenografts, whilst neither prodrug nor virus were active as single agents. This work highlights the potential for future clinical development of NTR-armed oncolytic viruses in combination with bioreductive prodrugs.
Collapse
Affiliation(s)
- Dean C Singleton
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand. .,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand.
| | - Alexandra M Mowday
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Chris P Guise
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Sophie P Syddall
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Sally Y Bai
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Dan Li
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Amir Ashoorzadeh
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Jeff B Smaill
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - William R Wilson
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Adam V Patterson
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| |
Collapse
|
3
|
Calcium Enabled Remote Loading of a Weak Acid Into pH-sensitive Liposomes and Augmented Cytosolic Delivery to Cancer Cells via the Proton Sponge Effect. Pharm Res 2022; 39:1181-1195. [PMID: 35229237 PMCID: PMC9197910 DOI: 10.1007/s11095-022-03206-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/16/2022] [Indexed: 11/05/2022]
Abstract
While delivery of chemotherapeutics to cancer cells by nanomedicines can improve therapeutic outcomes, many fail due to the low drug loading (DL), poor cellular uptake and endosomal entrapment. This study investigated the potential to overcome these limitations using pH-sensitive liposomes (PSL) empowered by the use of calcium acetate. An acidic dinitrobenzamide mustard prodrug SN25860 was used as a model drug, with non pH-sensitive liposomes (NPSL) as a reference. Calcium acetate as a remote loading agent allowed to engineer PSL- and NPSL-SN25860 with DL of > 31.1% (w/w). The IC50 of PSL-SN25860 was 21- and 141-fold lower than NPSL and free drug, respectively. At 48 h following injection of PSL-SN25860, NPSL-SN25860 and the free drug, drug concentrations in EMT6-nfsB murine breast tumors were 56.3 µg/g, 6.76 µg/g and undetectable (< 0.015 µg/g), respectively (n = 3). Meanwhile, the ex vivo tumor clonogenic assay showed 9.1%, 19.4% and 42.7% cell survival in the respective tumors. Live-cell imaging and co-localization analysis suggested endosomal escape was accomplished by destabilization of PSL followed by release of Ca2+ in endosomes allowing induction of a proton sponge effect. Subsequent endosomal rupture was observed approximately 30 min following endocytosis of PSL containing Ca2+. Additionally, calcium in liposomes promoted internalization of both PSL and NPSL. Taken together, this study demonstrated multifaceted functions of calcium acetate in promoting drug loading into liposomes, cellular uptake, and endosomal escape of PSL for efficient cytoplasmic drug delivery. The results shed light on designing nano-platforms for cytoplasmic delivery of various therapeutics.
Collapse
|
4
|
Interrogation of the Structure–Activity Relationship of a Lipophilic Nitroaromatic Prodrug Series Designed for Cancer Gene Therapy Applications. Pharmaceuticals (Basel) 2022; 15:ph15020185. [PMID: 35215297 PMCID: PMC8877822 DOI: 10.3390/ph15020185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 11/17/2022] Open
Abstract
PR-104A is a dual hypoxia/nitroreductase gene therapy prodrug by virtue of its ability to undergo either one- or two-electron reduction to its cytotoxic species. It has been evaluated extensively in pre-clinical GDEPT studies, yet off-target human aldo-keto reductase AKR1C3-mediated activation has limited its use. Re-evaluation of this chemical scaffold has previously identified SN29176 as an improved hypoxia-activated prodrug analogue of PR-104A that is free from AKR1C3 activation. However, optimization of the bystander effect of SN29176 is required for use in a GDEPT setting to compensate for the non-uniform distribution of therapeutic gene transfer that is often observed with current gene therapy vectors. A lipophilic series of eight analogues were synthesized from commercially available 3,4-difluorobenzaldehyde. Calculated octanol-water partition coefficients (LogD7.4) spanned > 2 orders of magnitude. 2D anti-proliferative and 3D multicellular layer assays were performed using isogenic HCT116 cells expressing E. coli NfsA nitroreductase (NfsA_Ec) or AKR1C3 to determine enzyme activity and measure bystander effect. A variation in potency for NfsA_Ec was observed, while all prodrugs appeared AKR1C3-resistant by 2D assay. However, 3D assays indicated that increasing prodrug lipophilicity correlated with increased AKR1C3 activation and NfsA_Ec activity, suggesting that metabolite loss from the cell of origin into media during 2D monolayer assays could mask cytotoxicity. Three prodrugs were identified as bono fide AKR1C3-negative candidates whilst maintaining activity with NfsA_Ec. These were converted to their phosphate ester pre-prodrugs before being taken forward into in vivo therapeutic efficacy studies. Ultimately, 2-(5-(bis(2-bromoethyl)amino)-4-(ethylsulfonyl)-N-methyl-2-nitrobenzamido)ethyl dihydrogen phosphate possessed a significant 156% improvement in median survival in mixed NfsA_Ec/WT tumors compared to untreated controls (p = 0.005), whilst still maintaining hypoxia selectivity comparable to PR-104A.
Collapse
|
5
|
Restoring Tumour Selectivity of the Bioreductive Prodrug PR-104 by Developing an Analogue Resistant to Aerobic Metabolism by Human Aldo-Keto Reductase 1C3. Pharmaceuticals (Basel) 2021; 14:ph14121231. [PMID: 34959631 PMCID: PMC8707548 DOI: 10.3390/ph14121231] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/20/2021] [Accepted: 11/22/2021] [Indexed: 12/28/2022] Open
Abstract
PR-104 is a phosphate ester pre-prodrug that is converted in vivo to its cognate alcohol, PR-104A, a latent alkylator which forms potent cytotoxins upon bioreduction. Hypoxia selectivity results from one-electron nitro reduction of PR-104A, in which cytochrome P450 oxidoreductase (POR) plays an important role. However, PR-104A also undergoes ‘off-target’ two-electron reduction by human aldo-keto reductase 1C3 (AKR1C3), resulting in activation in oxygenated tissues. AKR1C3 expression in human myeloid progenitor cells probably accounts for the dose-limiting myelotoxicity of PR-104 documented in clinical trials, resulting in human PR-104A plasma exposure levels 3.4- to 9.6-fold lower than can be achieved in murine models. Structure-based design to eliminate AKR1C3 activation thus represents a strategy for restoring the therapeutic window of this class of agent in humans. Here, we identified SN29176, a PR-104A analogue resistant to human AKR1C3 activation. SN29176 retains hypoxia selectivity in vitro with aerobic/hypoxic IC50 ratios of 9 to 145, remains a substrate for POR and triggers γH2AX induction and cell cycle arrest in a comparable manner to PR-104A. SN35141, the soluble phosphate pre-prodrug of SN29176, exhibited superior hypoxic tumour log cell kill (>4.0) to PR-104 (2.5–3.7) in vivo at doses predicted to be achievable in humans. Orthologues of human AKR1C3 from mouse, rat and dog were incapable of reducing PR-104A, thus identifying an underlying cause for the discrepancy in PR-104 tolerance in pre-clinical models versus humans. In contrast, the macaque AKR1C3 gene orthologue was able to metabolise PR-104A, indicating that this species may be suitable for evaluating the toxicokinetics of PR-104 analogues for clinical development. We confirmed that SN29176 was not a substrate for AKR1C3 orthologues across all four pre-clinical species, demonstrating that this prodrug analogue class is suitable for further development. Based on these findings, a prodrug candidate was subsequently identified for clinical trials.
Collapse
|
6
|
Chappel L, Wong LC, Leong CO, Mai CW, Meikle IT, Stanforth SP, Truong TV. The synthesis of trifluoromethylated N-nitroaryl-2-amino-1,3-dichloropropane derivatives and their evaluation as potential anti-cancer agents. Bioorg Med Chem Lett 2020; 30:126910. [PMID: 31882300 DOI: 10.1016/j.bmcl.2019.126910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 02/05/2023]
Abstract
Six N-nitroaryl-2-amino-1,3-dichloropropane derivatives have been prepared and evaluated against 18 cancer cell lines and two non-cancerous cell lines. Analysis of cell viability data and IC50 values indicated that the presence of a trifluoromethyl group in the nitroaryl moiety is an important structural feature associated with the compounds' cytotoxicities.
Collapse
Affiliation(s)
- Lucy Chappel
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| | - Lai Chun Wong
- Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University Malaysia, 57000 Kuala Lumpur, Malaysia
| | - Chee-Onn Leong
- Centre for Cancer and Stem Cells Research, Institute for Research, Development and Innovation, International Medical University Malaysia, 57000 Kuala Lumpur, Malaysia; Department of Life Sciences, School of Pharmacy, International Medical University Malaysia, 57000 Kuala Lumpur, Malaysia
| | - Chun-Wai Mai
- Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University Malaysia, 57000 Kuala Lumpur, Malaysia; Centre for Cancer and Stem Cells Research, Institute for Research, Development and Innovation, International Medical University Malaysia, 57000 Kuala Lumpur, Malaysia
| | - Ian T Meikle
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| | - Stephen P Stanforth
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK.
| | - Thang V Truong
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| |
Collapse
|
7
|
Asymmetric and Reduced Xanthene Fluorophores: Synthesis, Photochemical Properties, and Application to Activatable Fluorescent Probes for Detection of Nitroreductase. Molecules 2019; 24:molecules24173206. [PMID: 31484448 PMCID: PMC6749439 DOI: 10.3390/molecules24173206] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 08/31/2019] [Accepted: 09/02/2019] [Indexed: 12/20/2022] Open
Abstract
Xanthene fluorophores, including fluorescein, rhodol, and rhodamines, are representative classes of fluorescent probes that have been applied in the detection and visualization of biomolecules. “Turn on” activatable fluorescent probes, that can be turned on in response to enzymatic reactions, have been developed and prepared to reduce the high background signal of “always-on” fluorescent probes. However, the development of activity-based fluorescent probes for biological applications, using simple xanthene dyes, is hampered by their inefficient synthetic methods and the difficulty of chemical modifications. We have, thus, developed a highly efficient, versatile synthetic route to developing chemically more stable reduced xanthene fluorophores, based on fluorescein, rhodol, and rhodamine via continuous Pd-catalyzed cross-coupling. Their fluorescent nature was evaluated by monitoring fluorescence with variation in the concentration, pH, and solvent. As an application to activatable fluorescent probe, nitroreductase (NTR)-responsive fluorescent probes were also developed using the reduced xanthene fluorophores, and their fluorogenic properties were evaluated.
Collapse
|
8
|
Abstract
The nitro group is considered to be a versatile and unique functional group in medicinal chemistry. Despite a long history of use in therapeutics, the nitro group has toxicity issues and is often categorized as a structural alert or a toxicophore, and evidence related to drugs containing nitro groups is rather contradictory. In general, drugs containing nitro groups have been extensively associated with mutagenicity and genotoxicity. In this context, efforts toward the structure-mutagenicity or structure-genotoxicity relationships have been undertaken. The current Perspective covers various aspects of agents that contain nitro groups, their bioreductive activation mechanisms, their toxicities, and approaches to combat their toxicity issues. In addition, recent advances in the field of anticancer, antitubercular and antiparasitic agents containing nitro groups, along with a patent survey on hypoxia-activated prodrugs containing nitro groups, are also covered.
Collapse
Affiliation(s)
- Kunal Nepali
- School of Pharmacy, College of Pharmacy , Taipei Medical University , 250 Wuxing Street , Taipei 11031 , Taiwan
| | - Hsueh-Yun Lee
- School of Pharmacy, College of Pharmacy , Taipei Medical University , 250 Wuxing Street , Taipei 11031 , Taiwan
| | - Jing-Ping Liou
- School of Pharmacy, College of Pharmacy , Taipei Medical University , 250 Wuxing Street , Taipei 11031 , Taiwan
| |
Collapse
|
9
|
Chen W, Fan H, Balakrishnan K, Wang Y, Sun H, Fan Y, Gandhi V, Arnold LA, Peng X. Discovery and Optimization of Novel Hydrogen Peroxide Activated Aromatic Nitrogen Mustard Derivatives as Highly Potent Anticancer Agents. J Med Chem 2018; 61:9132-9145. [PMID: 30247905 DOI: 10.1021/acs.jmedchem.8b00559] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We describe several new aromatic nitrogen mustards with various aromatic substituents and boronic esters that can be activated with H2O2 to efficiently cross-link DNA. In vitro studies demonstrated the anticancer potential of these compounds at lower concentrations than those of other clinically used chemotherapeutics, such as melphalan and chlorambucil. In particular, compound 10, bearing an amino acid ester chain, is selectively cytotoxic toward breast cancer and leukemia cells that have inherently high levels of reactive oxygen species. Importantly, 10 was 10-14-fold more efficacious than melphalan and chlorambucil for triple-negative breast-cancer (TNBC) cells. Similarly, 10 is more toxic toward primary chronic-lymphocytic-leukemia cells than either chlorambucil or the lead compound, 9. The introduction of an amino acid side chain improved the solubility and permeability of 10. Furthermore, 10 inhibited the growth of TNBC tumors in xenografted mice without obvious signs of general toxicity, making this compound an ideal drug candidate for clinical development.
Collapse
Affiliation(s)
- Wenbing Chen
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery , University of Wisconsin, Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Heli Fan
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery , University of Wisconsin, Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Kumudha Balakrishnan
- Department of Experimental Therapeutics , MD Anderson Cancer Center , Houston , Texas 77030 , United States
| | | | | | | | - Varsha Gandhi
- Department of Experimental Therapeutics , MD Anderson Cancer Center , Houston , Texas 77030 , United States
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery , University of Wisconsin, Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Xiaohua Peng
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery , University of Wisconsin, Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| |
Collapse
|
10
|
Hong CR, Bogle G, Wang J, Patel K, Pruijn FB, Wilson WR, Hicks KO. Bystander Effects of Hypoxia-Activated Prodrugs: Agent-Based Modeling Using Three Dimensional Cell Cultures. Front Pharmacol 2018; 9:1013. [PMID: 30279659 PMCID: PMC6153434 DOI: 10.3389/fphar.2018.01013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/20/2018] [Indexed: 12/19/2022] Open
Abstract
Intra-tumor heterogeneity represents a major barrier to anti-cancer therapies. One strategy to minimize this limitation relies on bystander effects via diffusion of cytotoxins from targeted cells. Hypoxia-activated prodrugs (HAPs) have the potential to exploit hypoxia in this way, but robust methods for measuring bystander effects are lacking. The objective of this study is to develop experimental models (monolayer, multilayer, and multicellular spheroid co-cultures) comprising 'activator' cells with high expression of prodrug-activating reductases and reductase-deficient 'target' cells, and to couple these with agent-based models (ABMs) that describe diffusion and reaction of prodrugs and their active metabolites, and killing probability for each cell. HCT116 cells were engineered as activators by overexpressing P450 oxidoreductase (POR) and as targets by knockout of POR, with fluorescent protein and antibiotic resistance markers to enable their quantitation in co-cultures. We investigated two HAPs with very different pharmacology: SN30000 is metabolized to DNA-breaking free radicals under hypoxia, while the dinitrobenzamide PR104A generates DNA-crosslinking nitrogen mustard metabolites. In anoxic spheroid co-cultures, increasing the proportion of activator cells decreased killing of both activators and targets by SN30000. An ABM parameterized by measuring SN30000 cytotoxicity in monolayers and diffusion-reaction in multilayers accurately predicted SN30000 activity in spheroids, demonstrating the lack of bystander effects and that rapid metabolic consumption of SN30000 inhibited prodrug penetration. In contrast, killing of targets by PR104A in anoxic spheroids was markedly increased by activators, demonstrating that a bystander effect more than compensates any penetration limitation. However, the ABM based on the well-studied hydroxylamine and amine metabolites of PR104A did not fit the cell survival data, indicating a need to reassess its cellular pharmacology. Characterization of extracellular metabolites of PR104A in anoxic cultures identified more stable, lipophilic, activated dichloro mustards with greater tissue diffusion distances. Including these metabolites explicitly in the ABM provided a good description of activator and target cell killing by PR104A in spheroids. This study represents the most direct demonstration of a hypoxic bystander effect for PR104A to date, and demonstrates the power of combining mathematical modeling of pharmacokinetics/pharmacodynamics with multicellular culture models to dissect bystander effects of targeted drug carriers.
Collapse
Affiliation(s)
- Cho R. Hong
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Gib Bogle
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand
| | - Jingli Wang
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Kashyap Patel
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Frederik B. Pruijn
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - William R. Wilson
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand
| | - Kevin O. Hicks
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand
| |
Collapse
|
11
|
Copp JN, Mowday AM, Williams EM, Guise CP, Ashoorzadeh A, Sharrock AV, Flanagan JU, Smaill JB, Patterson AV, Ackerley DF. Engineering a Multifunctional Nitroreductase for Improved Activation of Prodrugs and PET Probes for Cancer Gene Therapy. Cell Chem Biol 2017; 24:391-403. [DOI: 10.1016/j.chembiol.2017.02.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/31/2016] [Accepted: 02/01/2017] [Indexed: 12/20/2022]
|
12
|
Lin S, Li Y, Zheng Y, Luo L, Sun Q, Ge Z, Cheng T, Li R. Design, synthesis and biological evaluation of quinazoline–phosphoramidate mustard conjugates as anticancer drugs. Eur J Med Chem 2017; 127:442-458. [DOI: 10.1016/j.ejmech.2016.12.055] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 12/26/2016] [Accepted: 12/26/2016] [Indexed: 11/26/2022]
|
13
|
Yang MM, Wilson WR, Wu Z. pH-Sensitive PEGylated liposomes for delivery of an acidic dinitrobenzamide mustard prodrug: Pathways of internalization, cellular trafficking and cytotoxicity to cancer cells. Int J Pharm 2017; 516:323-333. [DOI: 10.1016/j.ijpharm.2016.11.041] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/04/2016] [Accepted: 11/18/2016] [Indexed: 11/25/2022]
|
14
|
Burke PJ, Wong LC, Jenkins TC, Knox RJ, Meikle IT, Stanforth SP. Studies relating to the synthesis, enzymatic reduction and cytotoxicity of a series of nitroaromatic prodrugs. Bioorg Med Chem Lett 2016; 26:5851-5854. [PMID: 27876476 DOI: 10.1016/j.bmcl.2016.11.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 11/17/2022]
Abstract
A series of N-nitroarylated-3-chloromethyl-1,2,3,4-tetrahydroisoquinoline derivatives, several of which also possessed a trifluoromethyl substituent, were prepared and assessed as potential nitroaromatic prodrugs. The enzymatic reduction of these compounds and their cytotoxicities were studied. The compounds were cytotoxic, but this is probably not related to their enzymatic reduction.
Collapse
Affiliation(s)
- Philip J Burke
- Morvus Technology Ltd, Llanvetherine Court, Llanvetherine, Abergavenny NP7 8NL, UK
| | - Lai Chun Wong
- Department of Applied Sciences, University of Northumbria, Newcastle-upon-Tyne NE1 8ST, UK
| | - Terence C Jenkins
- Morvus Technology Ltd, Llanvetherine Court, Llanvetherine, Abergavenny NP7 8NL, UK
| | - Richard J Knox
- Morvus Technology Ltd, Llanvetherine Court, Llanvetherine, Abergavenny NP7 8NL, UK
| | - Ian T Meikle
- Department of Applied Sciences, University of Northumbria, Newcastle-upon-Tyne NE1 8ST, UK
| | - Stephen P Stanforth
- Department of Applied Sciences, University of Northumbria, Newcastle-upon-Tyne NE1 8ST, UK.
| |
Collapse
|
15
|
Mowday AM, Ashoorzadeh A, Williams EM, Copp JN, Silva S, Bull MR, Abbattista MR, Anderson RF, Flanagan JU, Guise CP, Ackerley DF, Smaill JB, Patterson AV. Rational design of an AKR1C3-resistant analog of PR-104 for enzyme-prodrug therapy. Biochem Pharmacol 2016; 116:176-87. [PMID: 27453434 DOI: 10.1016/j.bcp.2016.07.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/20/2016] [Indexed: 12/28/2022]
Abstract
The clinical stage anti-cancer agent PR-104 has potential utility as a cytotoxic prodrug for exogenous bacterial nitroreductases expressed from replicating vector platforms. However substrate selectivity is compromised due to metabolism by the human one- and two-electron oxidoreductases cytochrome P450 oxidoreductase (POR) and aldo-keto reductase 1C3 (AKR1C3). Using rational drug design we developed a novel mono-nitro analog of PR-104A that is essentially free of this off-target activity in vitro and in vivo. Unlike PR-104A, there was no biologically relevant cytotoxicity in cells engineered to express AKR1C3 or POR, under aerobic or anoxic conditions, respectively. We screened this inert prodrug analog, SN34507, against a type I bacterial nitroreductase library and identified E. coli NfsA as an efficient bioactivator using a DNA damage response assay and recombinant enzyme kinetics. Expression of E. coli NfsA in human colorectal cancer cells led to selective cytotoxicity to SN34507 that was associated with cell cycle arrest and generated a robust 'bystander effect' at tissue-like cell densities when only 3% of cells were NfsA positive. Anti-tumor activity of SN35539, the phosphate pre-prodrug of SN34507, was established in 'mixed' tumors harboring a minority of NfsA-positive cells and demonstrated marked tumor control following heterogeneous suicide gene expression. These experiments demonstrate that off-target metabolism of PR-104 can be avoided and identify the suicide gene/prodrug partnership of E. coli NfsA/SN35539 as a promising combination for development in armed vectors.
Collapse
Affiliation(s)
- Alexandra M Mowday
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Amir Ashoorzadeh
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Elsie M Williams
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Janine N Copp
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Shevan Silva
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Matthew R Bull
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Maria R Abbattista
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Robert F Anderson
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Jack U Flanagan
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Christopher P Guise
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - David F Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Jeff B Smaill
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Adam V Patterson
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1023, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland 1023, New Zealand.
| |
Collapse
|
16
|
Feng P, Zhang H, Deng Q, Liu W, Yang L, Li G, Chen G, Du L, Ke B, Li M. Real-Time Bioluminescence Imaging of Nitroreductase in Mouse Model. Anal Chem 2016; 88:5610-4. [PMID: 27197544 DOI: 10.1021/acs.analchem.6b01160] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Nitroreductase (NTR) is an endogenous reductase overexpressed in hypoxic tumors; however, its precise detection in living cells and animals remains a considerable challenge. Herein, we developed three reaction-based probes and a related bioluminescence assay for the real-time NTR detection. The high sensitivity and selectivity of probe 3, combined with its remarkable potential of bioluminescence imaging, affords a valuable approach for in vivo imaging of NTR in a tumor model mouse.
Collapse
Affiliation(s)
- Ping Feng
- Institute of Clinical Trials, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Huateng Zhang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (MOE), School of Pharmacy, Shandong University , Jinan, Shandong 250012, China
| | - Quankun Deng
- The Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Wei Liu
- The Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Linghui Yang
- The Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Guobo Li
- The Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Guo Chen
- The Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Lupei Du
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (MOE), School of Pharmacy, Shandong University , Jinan, Shandong 250012, China
| | - Bowen Ke
- The Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China
| | - Minyong Li
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (MOE), School of Pharmacy, Shandong University , Jinan, Shandong 250012, China
| |
Collapse
|
17
|
Piskov VB, Chernyshev VP, Karakotov SD. M-Dinitroaromatic Moiety as a Fragment of Biologically Active Compounds. Pharm Chem J 2016. [DOI: 10.1007/s11094-016-1361-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
18
|
Nitroreductase gene-directed enzyme prodrug therapy: insights and advances toward clinical utility. Biochem J 2015; 471:131-53. [PMID: 26431849 DOI: 10.1042/bj20150650] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This review examines the vast catalytic and therapeutic potential offered by type I (i.e. oxygen-insensitive) nitroreductase enzymes in partnership with nitroaromatic prodrugs, with particular focus on gene-directed enzyme prodrug therapy (GDEPT; a form of cancer gene therapy). Important first indications of this potential were demonstrated over 20 years ago, for the enzyme-prodrug pairing of Escherichia coli NfsB and CB1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide]. However, it has become apparent that both the enzyme and the prodrug in this prototypical pairing have limitations that have impeded their clinical progression. Recently, substantial advances have been made in the biodiscovery and engineering of superior nitroreductase variants, in particular development of elegant high-throughput screening capabilities to enable optimization of desirable activities via directed evolution. These advances in enzymology have been paralleled by advances in medicinal chemistry, leading to the development of second- and third-generation nitroaromatic prodrugs that offer substantial advantages over CB1954 for nitroreductase GDEPT, including greater dose-potency and enhanced ability of the activated metabolite(s) to exhibit a local bystander effect. In addition to forging substantial progress towards future clinical trials, this research is supporting other fields, most notably the development and improvement of targeted cellular ablation capabilities in small animal models, such as zebrafish, to enable cell-specific physiology or regeneration studies.
Collapse
|
19
|
Shen L, Schroeder M, Ogorzalek TL, Yang P, Wu FG, Marsh ENG, Chen Z. Surface orientation control of site-specifically immobilized nitro-reductase (NfsB). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5930-5938. [PMID: 24807676 DOI: 10.1021/la5016862] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate the control of enzyme orientation for enzymes chemically immobilized on surfaces. Nitro-reductase (NfsB) has the ability to reduce a broad range of nitro-containing compounds and has potential applications in a broad range of areas including the detection and decomposition of explosives. The enzyme was tethered through unique surface cysteine residues to a self-assembled monolayer (SAM) terminated with maleimide groups. One cysteine was introduced close to the active site (V424C), and the other, at a remote site (H360C). The surface-tethered NfsB variants were interrogated by a combination of surface-sensitive sum frequency generation (SFG) vibrational spectroscopy and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) to determine how the mode of attachment altered the enzyme's orientation. The activities of the two immobilized NfsB variants were measured and can be well correlated to the deduced orientations. The relationships among enzyme engineering, surface immobilization, enzyme orientation, and enzyme activity were revealed.
Collapse
Affiliation(s)
- Lei Shen
- Department of Chemistry and ‡Chemical Biology Graduate Program, University of Michigan , Ann Arbor, Michigan 48109, United States
| | | | | | | | | | | | | |
Collapse
|
20
|
Chen W, Han Y, Peng X. Aromatic nitrogen mustard-based prodrugs: activity, selectivity, and the mechanism of DNA cross-linking. Chemistry 2014; 20:7410-8. [PMID: 24806710 DOI: 10.1002/chem.201400090] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 12/26/2022]
Abstract
Three novel H2O2-activated aromatic nitrogen mustard prodrugs (6-8) are reported. These compounds contain a DNA alkylating agent connected to a H2O2-responsive trigger by different electron-withdrawing linkers so that they are inactive towards DNA but can be triggered by H2O2 to release active species. The activity and selectivity of these compounds towards DNA were investigated by measuring DNA interstrand cross-link (ICL) formation in the presence or absence of H2O2. An electron-withdrawing linker unit, such as a quaternary ammonia salt (6), a carboxyamide (7), and a carbonate group (8), is sufficient to deactivate the aromatic nitrogen mustard resulting in less than 1.5 % cross-linking formation. However, H2O2 can restore the activity of the effectors by converting a withdrawing group to a donating group, therefore increasing the cross-linking efficiency (>20 %). The stability and reaction sites of the ICL products were determined, which revealed that alkylation induced by 7 and 8 not only occurred at the purine sites but also at the pyrimidine site. For the first time, we isolated and characterized the monomer adducts formed between the canonical nucleosides and the aromatic nitrogen mustard (15) which supported that nitrogen mustards reacted with dG, dA, and dC. The activation mechanism was studied by NMR spectroscopic analysis. An in vitro cytotoxicity assay demonstrated that compound 7 with a carboxyamide linker dramatically inhibited the growth of various cancer cells with a GI50 of less than 1 μM, whereas compound 6 with a charged linker did not show any obvious toxicity in all cell lines tested. These data indicated that a neutral carboxyamide linker is preferable for developing nitrogen mustard prodrugs. Our results showed that 7 is a potent anticancer prodrug that can serve as a model compound for further development. We believe these novel aromatic nitrogen mustards will inspire further and effective applications.
Collapse
Affiliation(s)
- Wenbing Chen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer St, Milwaukee, WI 53211 (USA)
| | | | | |
Collapse
|
21
|
Foehrenbacher A, Secomb TW, Wilson WR, Hicks KO. Design of optimized hypoxia-activated prodrugs using pharmacokinetic/pharmacodynamic modeling. Front Oncol 2013; 3:314. [PMID: 24409417 PMCID: PMC3873531 DOI: 10.3389/fonc.2013.00314] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 12/11/2013] [Indexed: 01/17/2023] Open
Abstract
Hypoxia contributes to resistance of tumors to some cytotoxic drugs and to radiotherapy, but can in principle be exploited with hypoxia-activated prodrugs (HAP). HAP in clinical development fall into two broad groups. Class I HAP (like the benzotriazine N-oxides tirapazamine and SN30000), are activated under relatively mild hypoxia. In contrast, Class II HAP (such as the nitro compounds PR-104A or TH-302) are maximally activated only under extreme hypoxia, but their active metabolites (effectors) diffuse to cells at intermediate O2 and thus also eliminate moderately hypoxic cells. Here, we use a spatially resolved pharmacokinetic/pharmacodynamic (SR-PK/PD) model to compare these two strategies and to identify the features required in an optimal Class II HAP. The model uses a Green's function approach to calculate spatial and longitudinal gradients of O2, prodrug, and effector concentrations, and resulting killing in a digitized 3D tumor microregion to estimate activity as monotherapy and in combination with radiotherapy. An analogous model for a normal tissue with mild hypoxia and short intervessel distances (based on a cremaster muscle microvessel network) was used to estimate tumor selectivity of cell killing. This showed that Class II HAP offer advantages over Class I including higher tumor selectivity and greater freedom to vary prodrug diffusibility and rate of metabolic activation. The model suggests that the largest gains in class II HAP antitumor activity could be realized by optimizing effector stability and prodrug activation rates. We also use the model to show that diffusion of effector into blood vessels is unlikely to materially increase systemic exposure for realistic tumor burdens and effector clearances. However, we show that the tumor selectivity achievable by hypoxia-dependent prodrug activation alone is limited if dose-limiting normal tissues are even mildly hypoxic.
Collapse
Affiliation(s)
- Annika Foehrenbacher
- Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand
| | | | - William R. Wilson
- Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand
| | - Kevin O. Hicks
- Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
22
|
Prosser GA, Copp JN, Mowday AM, Guise CP, Syddall SP, Williams EM, Horvat CN, Swe PM, Ashoorzadeh A, Denny WA, Smaill JB, Patterson AV, Ackerley DF. Creation and screening of a multi-family bacterial oxidoreductase library to discover novel nitroreductases that efficiently activate the bioreductive prodrugs CB1954 and PR-104A. Biochem Pharmacol 2013; 85:1091-103. [PMID: 23399641 DOI: 10.1016/j.bcp.2013.01.029] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 01/14/2023]
Abstract
Two potentially complementary approaches to improve the anti-cancer strategy gene-directed enzyme prodrug therapy (GDEPT) are discovery of more efficient prodrug-activating enzymes, and development of more effective prodrugs. Here we demonstrate the utility of a flexible screening system based on the Escherichia coli SOS response to evaluate novel nitroreductase enzymes and prodrugs in concert. To achieve this, a library of 47 candidate genes representing 11 different oxidoreductase families was created and screened to identify the most efficient activators of two different nitroaromatic prodrugs, CB1954 and PR-104A. The most catalytically efficient nitroreductases were found in the NfsA and NfsB enzyme families, with NfsA homologues generally more active than NfsB. Some members of the AzoR, NemA and MdaB families also exhibited low-level activity with one or both prodrugs. The results of SOS screening in our optimised E. coli reporter strain SOS-R2 were generally predictive of the ability of nitroreductase candidates to sensitise E. coli to CB1954, and of the kcat/Km for each prodrug substrate at a purified protein level. However, we also found that not all nitroreductases express stably in human (HCT-116 colon carcinoma) cells, and that activity at a purified protein level did not necessarily predict activity in stably transfected HCT-116. These results highlight a need for all enzyme-prodrug partners for GDEPT to be assessed in the specific context of the vector and cell line that they are intended to target. Nonetheless, our oxidoreductase library and optimised screens provide valuable tools to identify preferred nitroreductase-prodrug combinations to advance to preclinical evaluation.
Collapse
Affiliation(s)
- Gareth A Prosser
- School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington, New Zealand
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
An unexpected ring contraction of two nitroaryl pro-drugs: conversion of N-(nitroaryl)-3-chloropiperidine derivatives into N-(nitroaryl)-2-chloromethylpyrrolidines. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.05.095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
24
|
Abstract
Anticancer prodrugs designed to target specifically tumor cells should increase therapeutic effectiveness and decrease systemic side effects in the treatment of cancer. Over the last 20 years, significant advances have been made in the development of anticancer prodrugs through the incorporation of triggers for reductive activation. Reductively activated prodrugs have been designed to target hypoxic tumor tissues, which are known to overexpress several endogenous reductive enzymes. In addition, exogenous reductive enzymes can be delivered to tumor cells through fusion with tumor-specific antibodies or overexpressed in tumor cells through gene delivery approaches. Many anticancer prodrugs have been designed to use both the endogenous and exogenous reductive enzymes for target-specific activation and these prodrugs often contain functional groups such as quinones, nitroaromatics, N-oxides, and metal complexes. Although no new agents have been approved for clinical use, several reductively activated prodrugs are in various stages of clinical trial. This review mainly focuses on the medicinal chemistry aspects of various classes of reductively activated prodrugs including design principles, structure-activity relationships, and mechanisms of activation and release of active drug molecules.
Collapse
Affiliation(s)
- Yu Chen
- Department of Pharmaceutical Chemistry, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | | |
Collapse
|
25
|
Vass SO, Jarrom D, Wilson WR, Hyde EI, Searle PF. E. coli NfsA: an alternative nitroreductase for prodrug activation gene therapy in combination with CB1954. Br J Cancer 2009; 100:1903-11. [PMID: 19455141 PMCID: PMC2690450 DOI: 10.1038/sj.bjc.6605094] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Prodrug activation gene therapy is a developing approach to cancer treatment, whereby prodrug-activating enzymes are expressed in tumour cells. After administration of a non-toxic prodrug, its conversion to cytotoxic metabolites directly kills tumour cells expressing the activating enzyme, whereas the local spread of activated metabolites can kill nearby cells lacking the enzyme (bystander cell killing). One promising combination that has entered clinical trials uses the nitroreductase NfsB from Escherichia coli to activate the prodrug, CB1954, to a potent bifunctional alkylating agent. NfsA, the major E. coli nitroreductase, has greater activity with nitrofuran antibiotics, but it has not been compared in the past with NfsB for the activation of CB1954. We show superior in vitro kinetics of CB1954 activation by NfsA using the NADPH cofactor, and show that the expression of NfsA in bacterial or human cells results in a 3.5- to 8-fold greater sensitivity to CB1954, relative to NfsB. Although NfsB reduces either the 2-NO2 or 4-NO2 positions of CB1954 in an equimolar ratio, we show that NfsA preferentially reduces the 2-NO2 group, which leads to a greater bystander effect with cells expressing NfsA than with NfsB. NfsA is also more effective than NfsB for cell sensitisation to nitrofurans and to a selection of alternative, dinitrobenzamide mustard (DNBM) prodrugs.
Collapse
Affiliation(s)
- S O Vass
- Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham, UK
| | | | | | | | | |
Collapse
|
26
|
Roldán MD, Pérez-Reinado E, Castillo F, Moreno-Vivián C. Reduction of polynitroaromatic compounds: the bacterial nitroreductases. FEMS Microbiol Rev 2008; 32:474-500. [PMID: 18355273 DOI: 10.1111/j.1574-6976.2008.00107.x] [Citation(s) in RCA: 288] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Most nitroaromatic compounds are toxic and mutagenic for living organisms, but some microorganisms have developed oxidative or reductive pathways to degrade or transform these compounds. Reductive pathways are based either on the reduction of the aromatic ring by hydride additions or on the reduction of the nitro groups to hydroxylamino and/or amino derivatives. Bacterial nitroreductases are flavoenzymes that catalyze the NAD(P)H-dependent reduction of the nitro groups on nitroaromatic and nitroheterocyclic compounds. Nitroreductases have raised a great interest due to their potential applications in bioremediation, biocatalysis, and biomedicine, especially in prodrug activation for chemotherapeutic cancer treatments. Different bacterial nitroreductases have been purified and their biochemical and kinetic parameters have been determined. The crystal structure of some nitroreductases have also been solved. However, the physiological role(s) of these enzymes remains unclear. Nitroreductase genes are widely spread within bacterial genomes, but are also found in archaea and some eukaryotic species. Although studies on regulation of nitroreductase gene expression are scarce, it seems that nitroreductase genes may be controlled by the MarRA and SoxRS regulatory systems that are involved in responses to several antibiotics and environmental chemical hazards and to specific oxidative stress conditions. This review covers the microbial distribution, types, biochemical properties, structure and regulation of the bacterial nitroreductases. The possible physiological functions and the biotechnological applications of these enzymes are also discussed.
Collapse
Affiliation(s)
- María Dolores Roldán
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain.
| | | | | | | |
Collapse
|
27
|
Helsby NA, Goldthorpe MA, Tang MHY, Atwell GJ, Smith EM, Wilson WR, Tingle MD. Influence of mustard group structure on pathways of in vitro metabolism of anticancer N-(2-hydroxyethyl)-3,5-dinitrobenzamide 2-mustard prodrugs. Drug Metab Dispos 2007; 36:353-60. [PMID: 17998296 DOI: 10.1124/dmd.107.018739] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The dinitrobenzamide mustards are a class of bioreductive nitro-aromatic anticancer prodrugs, of which a phosphorylated analog (PR-104) is currently in clinical development. They are bioactivated by tumor reductases to form DNA cross-linking cytotoxins. However, their biotransformation in normal tissues has not been examined. Here we report the aerobic in vitro metabolism of three N-(2 hydroxyethyl)-3,5-dinitrobenzamide 2-mustards and the corresponding nonmustard analog in human, mouse, rat, and dog hepatic S9 preparations. These compounds have a range of mustard structures (-N(CH(2)CH(2)X)(2) where X = H, Cl, Br, or OSO(2)Me). Four metabolic routes were identified: reduction of either nitro group, N-dealkylation of the mustard, plus O-acetylation, and O-glucuronidation of the hydroxyethyl side chain. Reduction of the nitro group ortho to the mustard resulted in intramolecular alkylation and is considered to be an inactivation pathway, whereas reduction of the nitro group para to the mustard generated potential DNA cross-linking cytotoxins. N-Dealkylation inactivated the mustard moiety but may result in the formation of toxic acetaldehyde derivatives. Increasing the size of the nitrogen mustard leaving group abrogated the ortho-nitroreduction and N-dealkylation routes and thereby improved overall metabolic stability but had little effect on aerobic para-nitroreduction. All four compounds underwent O-glucuronidation of the hydroxyethyl side chain and further studies to elucidate the relative importance of this pathway in vivo are in progress.
Collapse
Affiliation(s)
- Nuala A Helsby
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
| | | | | | | | | | | | | |
Collapse
|
28
|
Singleton DC, Li D, Bai SY, Syddall SP, Smaill JB, Shen Y, Denny WA, Wilson WR, Patterson AV. The nitroreductase prodrug SN 28343 enhances the potency of systemically administered armed oncolytic adenovirus ONYX-411NTR. Cancer Gene Ther 2007; 14:953-67. [DOI: 10.1038/sj.cgt.7701088] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
29
|
Hicks KO, Myint H, Patterson AV, Pruijn FB, Siim BG, Patel K, Wilson WR. Oxygen Dependence and Extravascular Transport of Hypoxia-Activated Prodrugs: Comparison of the Dinitrobenzamide Mustard PR-104A and Tirapazamine. Int J Radiat Oncol Biol Phys 2007; 69:560-71. [PMID: 17869669 DOI: 10.1016/j.ijrobp.2007.05.049] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2007] [Revised: 05/28/2007] [Accepted: 05/29/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE To compare oxygen dependence and tissue transport properties of a new hypoxia-activated prodrug, PR-104A, with tirapazamine, and to evaluate the implications for antitumor activity when combined with radiotherapy. METHODS AND MATERIALS Oxygen dependence of cytotoxicity was measured by clonogenic assay in SiHa cell suspensions. Tissue transport parameters were determined using SiHa multicellular layers. Spatially resolved pharmacokinetic (PK) and pharmacodynamic (PD) models were developed to predict cell killing in SiHa tumors and tested by clonogenic assay 18 h after treatment with the corresponding phosphate ester, PR-104. RESULTS The K-value (oxygen concentration to halve cytotoxic potency) of PR-104A was 0.126 +/- 0.021 microM (10-fold lower than tirapazamine at 1.30 +/- 0.28 microM). The diffusion coefficient of PR-104A in multicellular layers (4.42 +/- 0.15 x 10(-7) cm2 s(-1)) was lower than that of tirapazamine (1.30 +/- 0.05 x 10(-6) cm2 s(-1)) but PK modeling predicted better penetration to hypoxic cells in tumors because of its slower metabolism. The tirapazamine PK/PD model successfully predicted the measured activity in combination with single-dose radiation against SiHa tumors, and the PR-104A model underpredicted the activity, which was greater for PR-104 than for tirapazamine (at equivalent host toxicity) both with radiation and as a single agent. CONCLUSION PR-104/PR-104A has different PK/PD properties from tirapazamine and superior activity with single-dose radiotherapy against SiHa xenografts. We have inferred that PR-104A is better able to kill cells at intermediate partial pressure of oxygen in tumors than implied by the PK/PD model, most likely because of a bystander effect resulting from diffusion of its activated metabolites from severely hypoxic zones.
Collapse
Affiliation(s)
- Kevin O Hicks
- Auckland Cancer Society Research Centre, University of Auckland School of Medical Sciences, Auckland, New Zealand.
| | | | | | | | | | | | | |
Collapse
|
30
|
Synthesis of asymmetric halomesylate mustards with aziridineethanol/alkali metal halides: application to an improved synthesis of the hypoxia prodrug PR-104. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.04.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|