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Fu Q, Shen S, Sun P, Gu Z, Bai Y, Wang X, Liu Z. Bioorthogonal chemistry for prodrug activation in vivo. Chem Soc Rev 2023; 52:7737-7772. [PMID: 37905601 DOI: 10.1039/d2cs00889k] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Prodrugs have emerged as a major strategy for addressing clinical challenges by improving drug pharmacokinetics, reducing toxicity, and enhancing treatment efficacy. The emergence of new bioorthogonal chemistry has greatly facilitated the development of prodrug strategies, enabling their activation through chemical and physical stimuli. This "on-demand" activation using bioorthogonal chemistry has revolutionized the research and development of prodrugs. Consequently, prodrug activation has garnered significant attention and emerged as an exciting field of translational research. This review summarizes the latest advancements in prodrug activation by utilizing bioorthogonal chemistry and mainly focuses on the activation of small-molecule prodrugs and antibody-drug conjugates. In addition, this review also discusses the opportunities and challenges of translating these advancements into clinical practice.
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Affiliation(s)
- Qunfeng Fu
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
- Changping Laboratory, Beijing 102206, China
| | - Siyong Shen
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Pengwei Sun
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Zhi Gu
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Yifei Bai
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Xianglin Wang
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Zhibo Liu
- Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
- Changping Laboratory, Beijing 102206, China
- Peking University-Tsinghua University Center for Life Sciences, Peking University, Beijing 100871, China
- Key Laboratory of Carcinogenesis and Translational Research of Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China
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Pancreatic adenocarcinoma preferentially takes up and is suppressed by synthetic nanoparticles carrying apolipoprotein A-II and a lipid gemcitabine prodrug in mice. Cancer Lett 2020; 495:112-122. [PMID: 32949679 DOI: 10.1016/j.canlet.2020.08.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 08/13/2020] [Accepted: 08/28/2020] [Indexed: 11/21/2022]
Abstract
We hypothesised that synthetic HDL nanoparticles carrying a gemcitabine prodrug and apolipoprotein A-II (sHDLGemA2) would target scavenger receptor-B1 (SR-B1) to preferentially and safely deliver gemcitabine into pancreatic ductal adenocarcinoma (PDAC). We designed, manufactured and characterised sHDLGemA2 nanoparticles sized ~130 nm, incorporating 20 mol% of a gemcitabine prodrug within the lipid bilayer, which strengthens on adding ApoA-II. We measured their ability to inhibit growth in cell lines and cell-derived and patient-derived murine PDAC xenografts. Fluorescent-labelled sHDLGemA2 delivered gemcitabine inside xenografts. Xenograft levels of active gemcitabine after sHDLGemA2 were similar to levels after high-dose free gemcitabine. Growth inhibition in mice receiving 4.5 mg gemcitabine/kg/d, carried in sHDLGemA2, was equivalent to inhibition after high-dose (75 mg/kg/d) free gemcitabine, and greater than inhibition after low-dose (4.5 mg/kg/d) free gemcitabine. sHDLGemA2 slowed growth in semi-resistant cells and a resistant human xenograft. sHDLGemA2 targeted xenografts more effectively than sHDLGemA1. SR-B1 was over-expressed in PDAC cells and xenografts. Targeting by ApoA-II was suppressed by anti-SR-B1. Because sHDLGemA2 provided only ~6% of the free gemcitabine dose for an equivalent response, patient side effects can be greatly reduced, and the sHDLGemA2 concept should be developed through clinical trials.
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Takaoka T, Shibamoto Y, Matsuo M, Sugie C, Murai T, Ogawa Y, Miyakawa A, Manabe Y, Kondo T, Nakajima K, Okazaki D, Tsuchiya T. Biological effects of hydrogen peroxide administered intratumorally with or without irradiation in murine tumors. Cancer Sci 2017. [PMID: 28627761 PMCID: PMC5581514 DOI: 10.1111/cas.13302] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Despite insufficient laboratory data, radiotherapy after intratumoral injection of hydrogen peroxide (H2O2) is increasingly being used clinically for radioresistant tumors. Especially, this treatment might become an alternative definitive treatment for early and advanced breast cancer in patients who refuse any type of surgery. The purpose of this study was to investigate the biological effects and appropriate combination methods of irradiation and H2O2in vivo. SCCVII tumor cells transplanted into the legs of C3H/HeN mice were used. Chronological changes of intratumoral distribution of oxygen bubbles after injection of H2O2 were investigated using computed tomography. The effects of H2O2 alone and in combination with single or five‐fraction irradiation were investigated using a growth delay assay. The optimal timing of H2O2 injection was investigated. Immunostaining of tumors was performed using the hypoxia marker pimonidazole. Oxygen bubbles decreased gradually and almost disappeared after 24 h. Administration of H2O2 produced 2–3 days’ tumor growth delay. Tumor regrowth was slowed further when H2O2 was injected before irradiation. The group irradiated immediately after H2O2 injection showed the longest tumor growth delay. Dose‐modifying factors were 1.7–2.0 when combined with single irradiation and 1.3–1.5 with fractionated irradiation. Pimonidazole staining was weaker in tumors injected with H2O2. H2O2 injection alone had modest antitumor effects. Greater tumor growth delays were demonstrated by combining irradiation and H2O2 injection. The results of the present study could serve as a basis for evaluating results of various clinical studies on this treatment.
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Affiliation(s)
- Taiki Takaoka
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yuta Shibamoto
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Masayuki Matsuo
- Department of Radiology, Gifu University School of Medicine, Gifu, Japan
| | - Chikao Sugie
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Taro Murai
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yasutaka Ogawa
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Akifumi Miyakawa
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yoshihiko Manabe
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takuhito Kondo
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Koichiro Nakajima
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Dai Okazaki
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takahiro Tsuchiya
- Department of Radiology, Nagoya City University Hospital, Nagoya, Japan
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Rezaee Z, Yadollahpour A, Bayati V, Negad Dehbashi F. Gold nanoparticles and electroporation impose both separate and synergistic radiosensitizing effects in HT-29 tumor cells: an in vitro study. Int J Nanomedicine 2017; 12:1431-1439. [PMID: 28260889 PMCID: PMC5327907 DOI: 10.2147/ijn.s128996] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Radiation therapy (RT) is the gold standard treatment for more than half of known tumors. Despite recent improvements in RT efficiency, the side effects of ionizing radiation (IR) in normal tissues are a dose-limiting factor that restricts higher doses in tumor treatment. One approach to enhance the efficiency of RT is the application of radiosensitizers to selectively increase the dose at the tumor site. Gold nanoparticles (GNPs) and electroporation (EP) have shown good potential as radiosensitizers for RT. This study aims to investigate the sensitizing effects of EP, GNPs, and combined GNPs-EP on the dose enhancement factor (DEF) for 6 MV photon energy. METHODS Radiosensitizing effects of EP, GNPs, and combinations of GNPs-EP were comparatively investigated in vitro for intestinal colon cancer (HT-29) and Chinese hamster ovary (CHO) cell lines by MTT assay and colony formation assay at 6 MV photon energy in six groups: IR (control group), GNPs+IR, GNPs (24 h)+IR, EP+IR, GNPs+EP+IR, and GNPs (24 h)+EP+IR. RESULTS Treatment of both cell lines with EP, GNPs, and combined GNPs-EP significantly enhanced the response of cells to irradiation. However, the HT-29 showed higher DEF values for all groups. In addition, the DEF value for HT-29 cells for GNPs+IR, GNPs (24 h)+IR, EP+IR, GNPs+EP+IR, and GNPs (24 h)+EP+IR was, respectively, 1.17, 1.47, 1.36, 2.61, and 2.89, indicating synergistic radiosensitizing effect for the GNPs (24 h)+EP+IR group. Furthermore, the synergistic effect was observed just for HT-29 tumor cell lines. CONCLUSION Combined GNPs-EP protocols induced synergistic radiosensitizing effect in HT-29 cells, and the effect is also tumor specific. This combined therapy can be beneficially used for the treatment of intrinsically less radiosensitive tumors.
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Affiliation(s)
- Zohre Rezaee
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Avhaz, Iran
- Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Yadollahpour
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Avhaz, Iran
- Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Vahid Bayati
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Avhaz, Iran
| | - Fereshteh Negad Dehbashi
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Avhaz, Iran
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Synthesis and one-electron reduction characteristics of radiation-activated prodrugs possessing two 5-fluorodeoxyuridine units. Bioorg Med Chem 2012; 20:5164-8. [DOI: 10.1016/j.bmc.2012.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/02/2012] [Accepted: 07/03/2012] [Indexed: 11/20/2022]
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Tanabe K, Ishizaki J, Ando Y, Ito T, Nishimoto SI. Reductive activation of 5-fluorodeoxyuridine prodrug possessing azide methyl group by hypoxic X-irradiation. Bioorg Med Chem Lett 2012; 22:1682-5. [DOI: 10.1016/j.bmcl.2011.12.106] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 12/21/2011] [Accepted: 12/22/2011] [Indexed: 11/30/2022]
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Tanabe K, Ito T, Nishimoto SI. Radiolytic Reduction Characteristics of Artificial Oligodeoxynucleotides Possessing 2-Oxoalkyl Group or Disulfide Bonds. J Nucleic Acids 2011; 2011:816207. [PMID: 21860782 PMCID: PMC3153922 DOI: 10.4061/2011/816207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 05/20/2011] [Indexed: 11/30/2022] Open
Abstract
A number of advances have been made in the development of modified oligodeoxynucleotides (ODNs), and chemical or physical properties of which are controlled by external stimuli. These intelligent ODNs are promising for the next generation of gene diagnostics and therapy. This paper focuses on the molecular design of artificial ODNs that are activated by X-irradiation and their applications to regulation of hybridization properties, conformation change, radiation-activated DNAzyme, and decoy molecules.
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Affiliation(s)
- Kazuhito Tanabe
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan
| | - Takeo Ito
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan
| | - Sei-ichi Nishimoto
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan
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Brun E, Sanche L, Sicard-Roselli C. Parameters governing gold nanoparticle X-ray radiosensitization of DNA in solution. Colloids Surf B Biointerfaces 2009; 72:128-34. [DOI: 10.1016/j.colsurfb.2009.03.025] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Revised: 03/26/2009] [Accepted: 03/26/2009] [Indexed: 10/20/2022]
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Hirata N, Fujisawa Y, Tanabe K, Harada H, Hiraoka M, Nishimoto SI. Radiolytic activation of a cytarabine prodrug possessing a 2-oxoalkyl group: one-electron reduction and cytotoxicity characteristics. Org Biomol Chem 2009; 7:651-4. [DOI: 10.1039/b816194a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tanabe K, Ebihara M, Hirata N, Nishimoto SI. Radiolytic one-electron reduction characteristics of tyrosine derivative caged by 2-oxopropyl group. Bioorg Med Chem Lett 2008; 18:6126-9. [PMID: 18930655 DOI: 10.1016/j.bmcl.2008.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 10/02/2008] [Accepted: 10/03/2008] [Indexed: 10/21/2022]
Abstract
We employed X-irradiation to activate a caged amino acid with a 2-oxoalkyl group. We designed and synthesized tyrosine derivative caged by a 2-oxoalkyl group (Tyr(Oxo)) to evaluate its radiolytic one-electron reduction characteristics in aqueous solution. Upon hypoxic X-irradiation, Tyr(Oxo) released a 2-oxopropyl group to form the corresponding uncaged tyrosine. In addition, radiolysis of dipeptides containing Tyr(Oxo) revealed that the efficiency of radiolytic removal of 2-oxopropyl group increased significantly by the presence of neighboring aromatic amino acids.
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Affiliation(s)
- Kazuhito Tanabe
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan.
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Hainfeld JF, Dilmanian FA, Slatkin DN, Smilowitz HM. Radiotherapy enhancement with gold nanoparticles. J Pharm Pharmacol 2008; 60:977-85. [PMID: 18644191 DOI: 10.1211/jpp.60.8.0005] [Citation(s) in RCA: 427] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Gold is an excellent absorber of X-rays. If tumours could be loaded with gold, this would lead to a higher dose to the cancerous tissue compared with the dose received by normal tissue during a radiotherapy treatment. Calculations indicate that this dose enhancement can be significant, even 200% or greater. In this paper, the physical and biological parameters affecting this enhancement are discussed. Gold nanoparticles have shown therapeutic efficacy in animal trials and these results are reviewed. Some 86% long-term (>1 year) cures of EMT-6 mouse mammary subcutaneous tumours was achieved with an intravenous injection of gold nanoparticles before irradiation with 250-kVp photons, whereas only 20% were cured with radiation alone. The clinical potential of this approach is also discussed.
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Affiliation(s)
- James F Hainfeld
- Nanoprobes, Inc., 95 Horseblock Road, Yaphank, NY 11980-9710, USA.
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12
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Ito T, Tanabe K, Yamada H, Hatta H, Nishimoto SI. Radiation- and photo-induced activation of 5-fluorouracil prodrugs as a strategy for the selective treatment of solid tumors. Molecules 2008; 13:2370-84. [PMID: 18830160 PMCID: PMC6245186 DOI: 10.3390/molecules13102370] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 09/22/2008] [Accepted: 09/22/2008] [Indexed: 12/02/2022] Open
Abstract
5-Fluorouracil (5-FU) is used widely as an anticancer drug to treat solid cancers, such as colon, breast, rectal, and pancreatic cancers, although its clinical application is limited because 5-FU has gastrointestinal and hematological toxicity. Many groups are searching for prodrugs with functions that are tumor selective in their delivery and can be activated to improve the clinical utility of 5-FU as an important cancer chemotherapeutic agent. UV and ionizing radiation can cause chemical reactions in a localized area of the body, and these have been applied in the development of site-specific drug activation and sensitization. In this review, we describe recent progress in the development of novel 5-FU prodrugs that are activated site specifically by UV light and ionizing radiation in the tumor microenvironment. We also discuss the chemical mechanisms underlying this activation.
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Tanabe K, Hirata N, Harada H, Hiraoka M, Nishimoto SI. Emission under hypoxia: one-electron reduction and fluorescence characteristics of an indolequinone-coumarin conjugate. Chembiochem 2008; 9:426-32. [PMID: 18224643 DOI: 10.1002/cbic.200700458] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A characteristic feature of the reactivity of indolequinone derivatives, substituents of which can be removed by one-electron reduction under hypoxic conditions, was applied to the development of a new class of fluorescent probes for disease-relevant hypoxia. A reducing indolequinone parent molecule conjugated with fluorescent coumarin chromophores could suppress efficiently the fluorescence emission of the coumarin moieties by an intramolecular electron-transfer quenching mechanism and a conventional internal-filter effect. Under hypoxic conditions, however, the conjugate, denoted IQ-Cou, underwent a one-electron reduction triggered by X irradiation or the action of a reduction enzyme to release a fluorescent coumarin chromophore, whereupon an intense fluorescence emission with a maximum intensity at 420 nm was observed. The one-electron reduction of IQ-Cou was suppressed by molecular oxygen under aerobic conditions. IQ-Cou also showed intense fluorescence in a hypoxia-selective manner upon incubation with a cell lysate of the human fibrosarcoma cell line HT-1080. The IQ-Cou conjugate has several unique properties that are favorable for a fluorescent probe of hypoxia-specific imaging.
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Affiliation(s)
- Kazuhito Tanabe
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Nishikyo-ku, Kyoto 615-8510, Japan.
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Wouters A, Pauwels B, Lardon F, Vermorken JB. Review: implications of in vitro research on the effect of radiotherapy and chemotherapy under hypoxic conditions. Oncologist 2007; 12:690-712. [PMID: 17602059 DOI: 10.1634/theoncologist.12-6-690] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
As it is now well established that human solid tumors frequently contain a substantial fraction of cells that are hypoxic, more and more in vitro research is focusing on the impact of hypoxia on the outcome of radiotherapy and chemotherapy. Indeed, the efficacy of irradiation and many cytotoxic drugs relies on an adequate oxygen supply. Consequently, hypoxic regions in solid tumors often contain viable cells that are intrinsically more resistant to treatment with radiotherapy or chemotherapy. Moreover, efforts have been made to exploit hypoxia as a potential difference between malignant and normal tissues.Nowadays, a body of evidence indicates that oxygen deficiency clearly influences some major intracellular pathways such as those involved in cell proliferation, cell cycle progression, apoptosis, cell adhesion, and others. Obviously, when investigating the effects of radiotherapy or chemotherapy or both combined under hypoxic conditions, it is essential to consider the influences of hypoxia itself on the cell. In this review, we first focus on the effects of hypoxia per se on some critical biological pathways. Next, we sketch an overview of preclinical and clinical research on radiotherapy, chemotherapy, and chemoradiation under hypoxic conditions.
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Affiliation(s)
- An Wouters
- Laboratory of Cancer Research and Clinical Oncology, Department of Medical Oncology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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Tanabe K, Kanezaki H, Ishii H, Nishimoto SI. 2-Oxoalkyl caged oligonucleotides: one-electron reductive activation into emergence of ordinary hybridization property by hypoxic X-irradiation. Org Biomol Chem 2007; 5:1242-6. [PMID: 17406722 DOI: 10.1039/b618810a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionizing radiation triggers the activation of caged oligodeoxynucleotides (ODNs) with a 2-oxoalkyl leaving group to give the corresponding normal uncaged strands. We designed and synthesized ODNs caged by a 2-oxopropyl group at a given thymine N(3) position (d(oxo)T) to evaluate their one-electron reduction characteristics. Upon hypoxic X-radiolysis in aqueous solution, the caged ODNs released the 2-oxopropyl group to produce the corresponding uncaged ODNs. Digestion by a restriction enzyme Swa I revealed that caged ODN pre-irradiated in hypoxia could form an ordinary duplex with its complementary strand.
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Affiliation(s)
- Kazuhito Tanabe
- Department of Energy and Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Katsura campus, Kyoto, 615-8510, Japan.
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Tanabe K, Zhang Z, Ito T, Hatta H, Nishimoto SI. Current molecular design of intelligent drugs and imaging probes targeting tumor-specific microenvironments. Org Biomol Chem 2007; 5:3745-57. [DOI: 10.1039/b711244k] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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18
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Tanabe K, Makimura Y, Tachi Y, Imagawa-Sato A, Nishimoto SI. Hypoxia-selective activation of 5-fluorodeoxyuridine prodrug possessing indolequinone structure: radiolytic reduction and cytotoxicity characteristics. Bioorg Med Chem Lett 2005; 15:2321-4. [PMID: 15837317 DOI: 10.1016/j.bmcl.2005.03.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Accepted: 03/01/2005] [Indexed: 10/25/2022]
Abstract
We synthesized a 5-fluorodeoxyuridine (5-FdUrd) derivative possessing an indolequinone structure (IQ-FdUrd) to characterize the radiolytic reduction in aqueous solution and the radiation-activated cytotoxicity against EMT6/KU cells under hypoxic conditions. IQ-FdUrd released antitumor agent 5-FdUrd upon hypoxic, but not aerobic, irradiation with the G value of 0.38 x 10(-7) mol J(-1). Laser flash photolysis of IQ-FdUrd in Ar-purged aqueous solution with dimethylaniline as an electron donor gave rise to a transient absorption spectrum characteristic of semiquinone radical anion, which decayed via second order kinetics. It is most likely that bimolecular disproportionation of intermediate semiquinone radicals occurs to release 5-FdUrd. IQ-FdUrd showed enhanced cytotoxicity against EMT6/KU cells in a radiation dose-dependent manner upon hypoxic irradiation. IQ-FdUrd is potentially a prototype compound for new class of radiation-activated antitumor prodrugs that are useful for radiation treatment of hypoxic tumors.
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Affiliation(s)
- Kazuhito Tanabe
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan.
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19
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Shibamoto Y, Sugie C, Ito M, Ogino H. The Japanese experiences with hypoxia-targeting pharmacoradiotherapy: from hypoxic cell sensitisers to radiation-activated prodrugs. Expert Opin Pharmacother 2005; 5:2459-67. [PMID: 15571464 DOI: 10.1517/14656566.5.12.2459] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Tumour hypoxia is a negative factor in cancer radiotherapy. In order to overcome the problem, various pharmacotherapies have been investigated as an adjunct to radiotherapy. The use of hypoxic cell sensitisers is a classical strategy, and many new compounds have been developed and investigated. Development of more efficient compounds than those currently available seems difficult and clinical studies to prove the efficacy of the existing compounds are encouraged, especially in combination with radiosurgery, intraoperative radiotherapy, and interstitial irradiation, in which a single high dose of radiation is used. Following the advent of hypoxic cell sensitisers, hypoxic cytotoxins have become available. Among them, tirapazamine has already gained success when combined with cisplatin in non-small cell lung cancer. The beneficial effect of tirapazamine when combined with radiation needs to be determined. As a third-generation compound in this field, antitumour prodrugs that are activated by irradiation under hypoxic conditions via one-electron reduction have been proposed. Prodrugs of 5-fluorouracil and 5-fluoro-2'-deoxyuridine have shown in vivo as well as in vitro activity. Although clinical evaluation of the compounds is not warranted due to a relatively low in vivo effect, this strategy appears promising if the prodrug design can be applied to more potent agents that shall be developed in future.
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Affiliation(s)
- Yuta Shibamoto
- Nagoya City University, Department of Radiology, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
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Abstract
Systemic cytotoxic (antiproliferative) anticancer drugs rely primarily for their therapeutic effect on cytokinetic differences between cancer and normal cells. One approach aimed at improving the selectivity of tumor cell killing by such compounds is the use of less toxic prodrug forms that can be selectively activated in tumor tissue (tumor-activated prodrugs; TAP). There are several mechanisms potentially exploitable for the selective activation of TAP. Some utilize unique aspects of tumor physiology such as selective enzyme expression or hypoxia. Others are based on tumor-specific delivery techniques, including activation of prodrugs by exogenous enzymes delivered to tumor cells via monoclonal antibodies (ADEPT) or generated in tumor cells from DNA constructs containing the corresponding gene (GDEPT). Whichever activating mechanism is used, only a small proportion of the tumor cells are likely to be competent to activate the prodrug. Therefore, TAP need to fully exploit these "activator" cells by being capable of killing activation-incompetent cells as well via a "bystander effect." A wide variety of chemistries have been explored for the selective activation of TAP. Examples are given of the most important-the reduction of quinones, N-oxides, and nitroaromatics by endogenous enzymes or radiation; the cleavage of amides by endogenous peptidases; and hydrolytic metabolism by a variety of exogenous enzymes, including phosphatases, kinases, amidases, and glycosidases.
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Affiliation(s)
- William A Denny
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
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Shibamoto Y, Jeremic B. Biologic premises of combined radiation therapy and chemotherapy in lung cancer. Hematol Oncol Clin North Am 2004; 18:29-40. [PMID: 15005279 DOI: 10.1016/s0889-8588(03)00151-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
When radiation is combined with concurrent chemotherapy, independent cell kill and enhancement of tumor response may be expected. On the other hand, spatial cooperation may be the main rationale for sequential combination of the two modalities. Among many new agents being investigated, radiation-activated antitumor prodrugs have a therapeutic potential as a new method to effectively combine radiation and concurrent chemotherapy.
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Affiliation(s)
- Yuta Shibamoto
- Department of Radiology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
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Shibamoto Y, Tachi Y, Tanabe K, Hatta H, Nishimoto SI. In vitro and in vivo evaluation of novel antitumor prodrugs of 5-fluoro-2′-deoxyuridine activated by hypoxic irradiation. Int J Radiat Oncol Biol Phys 2004; 58:397-402. [PMID: 14751508 DOI: 10.1016/j.ijrobp.2003.09.048] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE We previously developed a novel antitumor prodrug that has a 2-oxopropyl substituent at the N(1) position of 5-fluorouracil (5-FU) and releases 5-FU via one-electron reduction on hypoxic irradiation. Although the compound was effective in vivo, its activity against murine tumors was not high enough to warrant clinical studies. Therefore, we developed a similar family of radiation-activated prodrugs of 5-fluoro-2'-deoxyuridine (FdUrd), which is generally more potent than 5-FU, and investigated their radiation chemical reactivity and in vitro and in vivo effects. METHODS AND MATERIALS Compounds bearing various 2-oxoalkyl substituents at the N(3) position of FdUrd were synthesized and investigated. After aerobic or hypoxic irradiation to the prodrugs dissolved in water or culture medium, release of FdUrd was measured using high-performance liquid chromatography. To investigate in vitro cytotoxicity, SCCVII and EMT6 cells in culture were irradiated in the presence of the prodrug under aerobic or hypoxic conditions, and then kept with the compound for 24 h. Cell survival was then measured using a colony assay. To investigate in vivo effects, the drug was injected intraperitoneally at a dose of 100 or 300 mg/kg into Balb/c mice bearing EMT6 tumors 30 min before irradiation. The tumor growth delay-time was then assessed. RESULTS In vitro, the prodrugs released FdUrd at G-values (molar numbers of molecules produced by 1 J of radiation energy) of 1.6-2.0 x 10(-7) mol/J after hypoxic irradiation. The G-values for FdUrd release with hypoxic irradiation were about 100-fold greater than those with aerobic irradiation. Among the prodrugs tested, OFU106 bearing a 2-oxocyclopentyl substituent released the highest amount of FdUrd in the culture medium, and it was subjected to further in vitro and in vivo assays. Although OFU106 administered alone showed no cytotoxicity up to a concentration of 0.2 mM, it produced an enhanced cytotoxic effect when administered before hypoxic irradiation and kept with the cells for 24 h. The enhancement ratios calculated at the surviving fraction of 1% were 1.35-1.4 at 0.04 mM and 1.45-1.5 at 0.2 mM. In vivo, however, administration of OFU106 (100 or 300 mg/kg) before 20 Gy of irradiation did not produce marked growth delays compared with 20 Gy of radiation alone. CONCLUSION On hypoxic irradiation in vitro, the prodrugs of FdUrd were activated as efficiently as were the prodrugs of 5-FU, but marked in vivo effects could not be detected. This strategy of prodrug design should be used in further development of radiation-activated prodrugs of more potent anticancer agents.
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Affiliation(s)
- Yuta Shibamoto
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
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Abstract
The occurrence of hypoxia in solid tumours is increasingly recognized as a limiting factor in the success of both radiotherapy and chemotherapy treatment, but at the same time offers a tumour-specific phenomenon for the activation of prodrugs. However, the design of clinically useful prodrugs that can be selectively activated in hypoxic cells has proved elusive. Specific reasons (activation by oxygen-insensitive two-electron reductases) have been proposed for the failure of quinone-based prodrugs, but a more general contributing factor may be inappropriate clinical trial design, and the failure to understand the critical importance of drug properties, such as efficient extra-vascular diffusion of the prodrug and back-diffusion of the activated drug in the tumour. Activation of prodrugs by therapeutic radiation and the use of hypoxia-selective gene therapy vectors, such as Clostridia, are exciting new mechanisms for prodrug research to explore, but are in much earlier stages of evaluation.
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Tanabe K, Mimasu Y, Eto A, Tachi Y, Sakakibara S, Mori M, Hatta H, Nishimoto SI. One-Electron reduction characteristics of N(3)-Substituted 5-fluorodeoxyuridines synthesized as radiation-Activated prodrugs. Bioorg Med Chem 2003; 11:4551-6. [PMID: 14527551 DOI: 10.1016/j.bmc.2003.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We designed and synthesized N(3)-substituted 5-fluorodeoxyuridines as radiation-activated prodrugs of the antitumor agent, 5-fluorodeoxyuridine (5-FdUrd). A series of 5-FdUrd derivatives possessing a 2-oxoalkyl group at the N(3)-position released 5-FdUrd in good yield via one-electron reduction initiated by hypoxic irradiation. Cytotoxicity of the 5-FdUrd derivative possessing the 2-oxocyclopentyl group (3d) was low, but was enhanced by hypoxic irradiation resulting in 5-FdUrd release.
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Affiliation(s)
- Kazuhito Tanabe
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
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Shibamoto Y, Mimasu Y, Tachi Y, Hatta H, Nishimoto S. Comparison of 5-fluorouracil and 5-fluoro-2'-deoxyuridine as an effector in radiation-activated prodrugs. J Chemother 2002; 14:390-6. [PMID: 12420858 DOI: 10.1179/joc.2002.14.4.390] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The purpose of this study was to clarify whether 5-fluoro-2'-deoxyuridine (FdUrd) is superior to 5-fluorouracil (5-FU) as an effector in the radiation-activated prodrugs which we have been developing. The in vitro cytotoxicity of 5-FU and FdUrd was compared in two murine tumor and four human pancreatic cancer cell lines using a colony assay and in vivo efficacy was compared with SCCVII tumor using a growth delay time assay. FdUrd was slightly more hydrophilic than 5-FU. In vitro, FdUrd was more efficient than 5-FU in two lines, whereas 5-FU was more efficient in two lines and the two drugs were almost equal in efficacy in the remaining two. The concentration to reduce tumor cell survival to 50% after 24-h drug exposure was 5-32 microM for both 5-FU and FdUrd in murine lines, while it was 30-210 microM in human pancreatic cancer cell lines. The difference in relative efficacy of the two drugs among these cell lines could not be attributed to the rate of intracellular uptake of the compounds. FdUrd was less toxic than 5-FU in C3H/He mice, and FdUrd was less efficient than 5-FU in SCCVII tumors in vivo. These results suggest that FdUrd is not necessarily more potent than 5-FU, and development of the FdUrd prodrugs may not necessarily turn out to be fruitful.
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Affiliation(s)
- Y Shibamoto
- Department of Radiology, Nagoya City University Medical School, Japan.
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Abstract
The administration of anti-cancer agents is currently associated with significant toxicity and lack of tumour specificity. Prodrugs are being designed to favourably alter the therapeutic index of these agents by improving their efficacy and reducing toxicity. Progress in the development of prodrugs including the cytotoxic agents most commonly used in cancer treatments namely 5-fluorouracil (5-FU), the anthracyclines, paclitaxel and platinum will be described. Many of these agents are at an early stage of development: however, this article will also describe those which have already made an impact in the clinic. It is likely that future improvements in care will come from refinement of the drugs already well established in clinical practice. In addition, this technology could be applied to novel agents with alternative cellular targets such as those involved in angiogenesis or in conferring metastatic potential. Thus, lessons learned with standard drugs may be applicable across a wider spectrum of therapeutics.
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Affiliation(s)
- M J Ferguson
- ANCHOR Unit, Aberdeen Royal Infirmary, Aberdeen, UK
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