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Qu H, Chen H, Cheng W, Wang Y, Xia Y, Zhang L, Ma B, Hu R, Xue X. A Supramolecular Assembly Strategy for Hydrophilic Drug Delivery towards Synergistic Cancer Treatment. Acta Biomater 2023; 164:407-421. [PMID: 37088157 DOI: 10.1016/j.actbio.2023.04.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/24/2023] [Accepted: 04/17/2023] [Indexed: 04/25/2023]
Abstract
To improve the drug loading, tumor targeting, and delivery simplicity of hydrophilic drugs, we propose a supramolecular assembly strategy that potentially benefits a wide range of hydrophilic drug delivery. Firstly, we choose a hydrophilic drug (tirapazamine) as a model drug to directly co-assemble with chlorin e6 (Ce6) at different molar ratios, and systematically evaluate the resultant Ce6-tirapazamine nanoparticles (CT NPs) in aspects of size distribution, polydispersity, morphology, optical properties and molecular dynamics simulation. Based on the assembling facts between Ce6 and tirapazamine, we summarize a plausible rule of the supramolecular assembly for hydrophilic drugs. To validate our findings, more drugs with increasing hydrophilicity, such as temozolomide, gemcitabine hydrochloride and 5-azacytidine, successfully co-assemble with Ce6 into nanostructures by following similar assembling behaviors, demonstrating that our assembling rule may guide a wide range of hydrophilic drug delivery. Next, the combination of Ce6 and tirapazamine was chosen as the representative to investigate the anti-tumor activities of the supramolecular assemblies. CT NPs showed synergistic anti-tumor efficacy, increased tumor accumulation and significant tumor progression and metastasis inhibition in tumor-bearing mice. We anticipate that the supramolecular assembly mechanism will provide broad guidance for developing easy-to-make but functional nanomedicines. STATEMENT OF SIGNIFICANCE: Although thousands of nanomedicines have been developed, only a few have been approved for clinical use. The manufacturing complexity significantly hinders the "bench-to-bed" translation of nanomedicines. Hence, we need to rethink how to conduct research on translational nanomedicines by avoiding more and more complex chemistry and complicated nanostructures. Here, we summarize a plausible rule according to multiple supramolecular assembly pairs and propose a supramolecular assembly strategy that can improve the drug loading, tumor targeting, and manufacturing simplicity of nanomedicine for hydrophilic drugs. The supramolecular assembly strategy would guide a broader range of drug delivery to provide a new paradigm for developing easy-to-make but multifunctional nanoformulations for synergistic cancer treatment.
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Affiliation(s)
- Haijing Qu
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Han Chen
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wei Cheng
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yanjun Wang
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China; Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Centre for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, China
| | - Yangyang Xia
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China; Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Centre for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, China
| | - Linghao Zhang
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Buyong Ma
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Rong Hu
- Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Centre for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, China.
| | - Xiangdong Xue
- School of Pharmacy, Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery, Shanghai Jiao Tong University, Shanghai, 200240, China.
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Vilaplana-Lopera N, Besh M, Moon EJ. Targeting Hypoxia: Revival of Old Remedies. Biomolecules 2021; 11:1604. [PMID: 34827602 PMCID: PMC8615589 DOI: 10.3390/biom11111604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 12/14/2022] Open
Abstract
Tumour hypoxia is significantly correlated with patient survival and treatment outcomes. At the molecular level, hypoxia is a major driving factor for tumour progression and aggressiveness. Despite the accumulative scientific and clinical efforts to target hypoxia, there is still a need to find specific treatments for tumour hypoxia. In this review, we discuss a variety of approaches to alter the low oxygen tumour microenvironment or hypoxia pathways including carbogen breathing, hyperthermia, hypoxia-activated prodrugs, tumour metabolism and hypoxia-inducible factor (HIF) inhibitors. The recent advances in technology and biological understanding reveal the importance of revisiting old therapeutic regimens and repurposing their uses clinically.
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Affiliation(s)
| | | | - Eui Jung Moon
- Department of Oncology, MRC Oxford Institute for Radiation Oncology, University of Oxford, Headington OX3 7DQ, UK; (N.V.-L.); (M.B.)
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Romero J, Maihom T, Limão-Vieira P, Probst M. Electronic structure and reactivity of tirapazamine as a radiosensitizer. J Mol Model 2021; 27:177. [PMID: 34021836 PMCID: PMC8140980 DOI: 10.1007/s00894-021-04771-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/21/2021] [Indexed: 11/30/2022]
Abstract
Tirapazamine (TP) has been shown to enhance the cytotoxic effects of ionizing radiation in hypoxic cells, thus making it a candidate for a radiosensitizer. This selective behavior is often directly linked to the abundance of O2. In this paper, we study the electronic properties of TP in vacuum, micro-hydrated from one up to three molecules of water and embedded in a continuum of water. We discuss electron affinities, charge distribution, and bond dissociation energies of TP, and find that these properties do not change significantly upon hydration. In agreement with its large electron affinity, and bond breaking triggered by electron attachment requires energies higher than 2.5 eV, ruling out the direct formation of bioactive TP radicals. Our results suggest, therefore, that the selective behavior of TP cannot be explained by a one-electron reduction from a neighboring O2 molecule. Alternatively, we propose that TP's hypoxic selectivity could be a consequence of O2 scavenging hydrogen radicals.
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Affiliation(s)
- José Romero
- Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal.
| | - Thana Maihom
- School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Rayong, 21210, Thailand
| | - Paulo Limão-Vieira
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal.
| | - Michael Probst
- Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
- School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Rayong, 21210, Thailand.
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Exploiting the cancer niche: Tumor-associated macrophages and hypoxia as promising synergistic targets for nano-based therapy. J Control Release 2017; 253:82-96. [PMID: 28285930 DOI: 10.1016/j.jconrel.2017.03.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/05/2017] [Accepted: 03/07/2017] [Indexed: 12/13/2022]
Abstract
The tumor microenvironment has been widely exploited as an active participant in tumor progression. Extensive reports have defined the dual role of tumor-associated macrophages (TAMs) in tumor development. The protumoral effect exerted by the M2 phenotype has been correlated with a negative outcome in most solid tumors. The high infiltration of immune cells in the hypoxic cores of advanced solid tumors leads to a chain reaction of stimuli that enhances the expression of protumoral genes, thrives tumor malignancy, and leads to the emergence of drug resistance. Many studies have shown therapeutic targeting systems, solely to TAMs or tumor hypoxia, however, novel therapeutics that target both features are still warranted. In the present review, we discuss the role of hypoxia in tumor development and the clinical outcome of hypoxia-targeted therapeutics, such as hypoxia-inducible factor (HIF-1) inhibitors and hypoxia-activated prodrugs. Furthermore, we review the state-of-the-art of macrophage-based cancer therapy. We thoroughly discuss the development of novel therapeutics that simultaneously target TAMs and tumor hypoxia. Nano-based systems have been highlighted as interesting strategies for dual modality treatments, with somewhat improved tissue extravasation. Such approach could be seen as a promising strategy to overcome drug resistance and enhance the efficacy of chemotherapy in advanced solid and metastatic tumors, especially when exploiting cell-based nanotherapies. Finally, we provide an in-depth opinion on the importance of exploiting the tumor microenvironment in cancer therapy, and how this could be translated to clinical practice.
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Hypoxia-targeting by tirapazamine (TPZ) induces preferential growth inhibition of nasopharyngeal carcinoma cells with Chk1/2 activation. Invest New Drugs 2009; 29:401-10. [PMID: 20013349 DOI: 10.1007/s10637-009-9356-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Accepted: 11/09/2009] [Indexed: 01/29/2023]
Abstract
Hypoxia is commonly developed in solid tumors, which contributes to metastasis as well as radio- and chemo-resistance. Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic head and neck cancer prevalent in Southeast Asia with a high incidence rate of 15-30/100,000 persons/year (comparable to that of pancreatic cancer in the US). Previous clinical studies in NPC showed that hypoxia is detected in almost 100% of primary tumors and overexpression of hypoxia markers correlated with poor clinical outcome. Tirapazamine (TPZ) is a synthetic hypoxia-activated prodrug, which preferentially forms cytotoxic and DNA-damaging free radicals under hypoxia, thus selectively eradicate hypoxic cells. Here, we hypothesized that specific hypoxia-targeting by this clinical trial agent may be therapeutic for NPC. Our findings demonstrated that under hypoxia, TPZ was able to induce preferential growth inhibition of NPC cells, which was associated with marked cell cycle arrest at S-phase and PARP cleavage (a hallmark of apoptosis). Examination of S-phase checkpoint regulators revealed that Chk1 and Chk2 were selectively activated by TPZ in NPC cells under hypoxia. Hypoxia-selectivity of TPZ was also demonstrated by preferential downregulation of several important hypoxia-induced markers (HIF-1α, CA IX and VEGF) under hypoxia. Furthermore, we demonstrated that TPZ was equally effective and hypoxia-selective even in the presence of the EBV oncoprotein, LMP1 or the EBV genome. In summary, encouraging results from this proof-of-concept study implicate the therapeutic potential of hypoxia-targeting approaches for the treatment of NPC.
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Reddy SB, Williamson SK. Tirapazamine: a novel agent targeting hypoxic tumor cells. Expert Opin Investig Drugs 2009; 18:77-87. [PMID: 19053884 DOI: 10.1517/13543780802567250] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Tumor hypoxia remains one of the greatest challenges in the treatment of solid tumors, as cancer cells in these regions are resistant to killing by radiation therapy and most anticancer drugs. Tirapazamine (TPZ) is a newer class of cytotoxic drugs with selective toxicity towards hypoxic mammalian cells. OBJECTIVE This article reviews the mechanism of action, toxicity and antitumor activity of the drug and provides insights into factors that may have contributed to the disappointing results in some of the Phase III trials. It also identifies the need to explore dependable markers of tumor hypoxia and limit future trials of this agent to patients who have significant populations of hypoxic tumor cells. METHODS We reviewed all clinical trials published to date and present a summary of the results. There are also several ongoing studies, the results of which are pending and may yet impact the clinical use of the drug. RESULTS/CONCLUSION Despite the very promising results obtained in various preclinical studies and early-Phase clinical trials, several Phase III trials have failed to demonstrate any survival benefit of adding TPZ to chemotherapy or radiation therapy in non-small cell lung cancer or head and neck cancer. Several clinical trials have yet to be completed and reported.
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Affiliation(s)
- Srini B Reddy
- University of Kansas Medical Center, Division of Hematology/Oncology, 2330 Shawnee Mission Parkway, Suite 210, Westwood, KS 66205, USA
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Hypoxia-specific drug tirapazamine does not abrogate hypoxic tumor cells in combination therapy with irinotecan and methylselenocysteine in well-differentiated human head and neck squamous cell carcinoma a253 xenografts. Neoplasia 2008; 10:857-65. [PMID: 18670644 DOI: 10.1593/neo.08424] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 05/19/2008] [Accepted: 05/20/2008] [Indexed: 02/04/2023] Open
Abstract
Well-differentiated hypoxic regions in head and neck squamous cell carcinoma like in A253 xenografts are avascular and, therefore, hinder drug delivery leading to drug resistance and tumor regrowth. Methylselenocysteine (MSC, 0.2 mg/mouse per day per oral for 35 days starting 7 days before the first irinotecan (CPT-11)) has been found to increase efficacy of a wide variety of chemotherapeutic agents including CPT-11 (100 mg/kg per week x 4 intravenously). Whereas CPT-11 leads to a 10% complete response (CR) in A253 xenografts, the combination of MSC and CPT-11 increased the CR to 70%. Surviving tumors were found to consist largely of avascular hypoxic regions. Here, we investigated the combination of tirapazamine (TPZ, 70 mg/kg per week intraperitoneal x 4 administered 3 or 72 hours before CPT-11), a bioreductive drug in clinical trial with selective toxicity for hypoxic cells, with MSC and CPT-11 in further enhancing the cure rates. Tumor response, change in tumor hypoxic regions, and DNA damage were monitored in vivo. Tirapazamine administered 3 hours before CPT-11 in combination with MSC + CPT-11 led to a lower tumor burden. Tirapazamine did not increase cure rate beyond that of MSC + CPT-11 combination and was instead found to decrease cures with no evidence of an increased DNA damage or a significant reduction in avascular hypoxic tumor regions. CD31 immunostaining in A253 demonstrated disruption of tumor vessels by TPZ that could lower cytotoxic drug delivery to carbonic anhydrase IX-positive hypoxic tumor cells and may explain at least partially these unexpected results.
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McKeown SR, Cowen RL, Williams KJ. Bioreductive drugs: from concept to clinic. Clin Oncol (R Coll Radiol) 2007; 19:427-42. [PMID: 17482438 DOI: 10.1016/j.clon.2007.03.006] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 02/20/2007] [Accepted: 03/09/2007] [Indexed: 11/19/2022]
Abstract
One of the key issues for radiobiologists is the importance of hypoxia to the radiotherapy response. This review addresses the reasons for this and primarily focuses on one aspect, the development of bioreductive drugs that are specifically designed to target hypoxic tumour cells. Four classes of compound have been developed since this concept was first proposed: quinones, nitroaromatics, aliphatic and heteroaromatic N-oxides. All share two characteristics: (1) they require hypoxia for activation and (2) this activation is dependent on the presence of specific reductases. The most effective compounds have shown the ability to enhance the anti-tumour efficacy of agents that kill better-oxygenated cells, i.e. radiation and standard cytotoxic chemotherapy agents such as cisplatin and cyclophosphamide. Tirapazamine (TPZ) is the most widely studied of the lead compounds. After successful pre-clinical in vivo combination studies it entered clinical trial; over 20 trials have now been reported. Although TPZ has enhanced some standard regimens, the results are variable and in some combinations toxicity was enhanced. Banoxantrone (AQ4N) is another agent that is showing promise in early phase I/II clinical trials; the drug is well tolerated, is known to locate in the tumour and can be given in high doses without major toxicities. Mitomycin C (MMC), which shows some bioreductive activation in vitro, has been tested in combination trials. However, it is difficult to assign the enhancement of its effects to targeting of the hypoxic cells because of the significant level of its hypoxia-independent toxicity. More specific analogues of MMC, e.g. porfiromycin and apaziquone (EO9), have had variable success in the clinic. Other new drugs that have good pre-clinical profiles are PR 104 and NLCQ-1; data on their clinical safety/efficacy are not yet available. This paper reviews the pre-clinical data and discusses the clinical studies that have been reported.
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Affiliation(s)
- S R McKeown
- Institute of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
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Aquino VM, Weitman SD, Winick NJ, Blaney S, Furman WL, Kepner JL, Bonate P, Krailo M, Qu W, Bernstein M. Phase I Trial of Tirapazamine and Cyclophosphamide in Children With Refractory Solid Tumors: A Pediatric Oncology Group Study. J Clin Oncol 2004; 22:1413-9. [PMID: 15084615 DOI: 10.1200/jco.2004.07.111] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose To determine the dose limiting toxicity (DLT), maximum-tolerated dose (MTD), and pharmacokinetic profile of tirapazamine (Sanofi Synthelabo Research, Malvern, PA) combined with cyclophosphamide in children with recurrent solid tumors. Patients and Methods Patients received a 2-hour infusion of tirapazamine, followed by 1,500 mg/m2 cyclophosphamide, and mesna once every 3 weeks. Dose escalation of tirapazamine began at 250 mg/m2 and was increased by 30% in subsequent cohorts. If DLT was hematologic, less-heavily pretreated patients were to be enrolled until their DLTs were encountered, and MTDs defined. Pharmacokinetic profiles were also characterized. Results Twenty-three patients were enrolled onto the study. Pharmacokinetic data were calculated for 22 patients. Prolonged neutropenia was the DLT at 420 mg/m2 in heavily pretreated patients. Grade 3, reversible ototoxicity was the DLT in less-heavily pretreated patients at 420 mg/m2. Two (one with neuroblastoma and one with rhabdomyosarcoma) had partial responses. One child with neuroblastoma had prolonged stable disease (10 cycles) at a dose of 250 mg/m2. This patient had disease detectable in the bone marrow only and all evidence of bone marrow involvement resolved for 17 cycles of therapy. Four other patients had stable disease. An apparent dose-proportional increase in tirapazamine maximal concentration and area under the curvelast was observed. Tirapazamine clearance, volume of distribution at steady-state, and terminal half-life did not appear to be dose-dependent. Conclusion The recommended dose of tirapazamine given with 1,500 mg/m2 of cyclophosphamide once every 3 weeks is 325 mg/m2. Neutropenia and ototoxicity were dose-limiting. Based on early evidence of antitumor activity, additional studies appear warranted.
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Affiliation(s)
- Victor M Aquino
- University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA.
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Cowen RL, Williams KJ, Chinje EC, Jaffar M, Sheppard FCD, Telfer BA, Wind NS, Stratford IJ. Hypoxia targeted gene therapy to increase the efficacy of tirapazamine as an adjuvant to radiotherapy: reversing tumor radioresistance and effecting cure. Cancer Res 2004; 64:1396-402. [PMID: 14973055 DOI: 10.1158/0008-5472.can-03-2698] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Solid tumors are characterized by regions of hypoxia that are inherently resistant to both radiotherapy and some chemotherapy. To target this resistant population, bioreductive drugs that are preferentially toxic to tumor cells in a hypoxic environment are being evaluated in clinical trials; the lead compound, tirapazamine (TPZ), is being used in combination with cisplatin and/or with radiotherapy. Crucially, tumor response to TPZ is also dependent on the cellular complement of reductases. In particular, NADPH:cytochrome P450 reductase (P450R) plays a major role in the metabolic activation of TPZ. In a gene-directed enzyme prodrug therapy (GDEPT) approach using adenoviral delivery, we have overexpressed human P450R specifically within hypoxic cells in tumors, with the aim of harnessing hypoxia as a trigger for both enzyme expression and drug metabolism. The adenovirus used incorporates the hypoxia-responsive element (HRE) from the lactate dehydrogenase gene in a minimal SV40 promoter context upstream of the cDNA for P450R. In a human tumor model in which TPZ alone does not potentiate radiotherapeutic outcome (HT1080 fibrosarcoma), we witnessed complete tumor regression when tumors were virally transduced before treatment.
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Affiliation(s)
- Rachel L Cowen
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Coupland III Building, Oxford Road, Manchester M13 9PL, UK.
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Hoff PM, Saad ED, Ravandi-Kashani F, Czerny E, Pazdur R. Phase I trial of i.v. administered tirapazamine plus cyclophosphamide. Anticancer Drugs 2001; 12:499-503. [PMID: 11459995 DOI: 10.1097/00001813-200107000-00002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Our objective was to determine the maximum tolerated doses of tirapazamine and cyclophosphamide given i.v. in combination. Eligible patients had advanced solid tumors refractory to conventional treatment. Tirapazamine (escalated from 80 to 390 mg/m(2)) was given i.v. over 2 h and followed by cyclophosphamide over 1 h. The cyclophosphamide dose was fixed at 1000 mg/m(2) until the tirapazamine dose of 390 mg/m(2) was reached. Once that dose of tirapazamine was reached, the cyclophosphamide dose was escalated to 1250 and 1500 mg/m(2). Twenty-eight patients were enrolled. The dose-limiting toxicity was granulocytopenia. One patient had transient deafness for 2 days. Four other patients had grade 1 ototoxicity. Grade 1 and 2 muscle cramps were observed at all dose levels. Other toxic effects observed included fatigue, nausea, vomiting, headache, diarrhea, drug fever, elevated transaminases and elevated creatine phosphokinase. Three patients had stable disease and the longest time to progression was 5 months. The combination of tirapazamine and cyclophosphamide is feasible, and the dose-limiting toxicity is granulocytopenia. The use of growth factors could possibly allow escalation of tirapazamine doses in future phase II trials. Without growth factor support, the recommended doses of tirapazamine and cyclophosphamide when administered in this schedule are 260 and 1000 mg/m(2), respectively.
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Affiliation(s)
- P M Hoff
- Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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Yuan X, Tabassi K, Williams JA. Implantable polymers for tirapazamine treatments of experimental intracranial malignant glioma. RADIATION ONCOLOGY INVESTIGATIONS 1999; 7:218-30. [PMID: 10492162 DOI: 10.1002/(sici)1520-6823(1999)7:4<218::aid-roi3>3.0.co;2-c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Malignant gliomas remain refractory to intensive radiotherapy and cellular hypoxia enhances clinical radioresistance. Under hypoxic conditions, the benzotriazine di-N-oxide (3-amino-1,2,4-benzotriazine 1,4-dioxide) (tirapazamine) is reduced to yield a free-radical intermediate that results in DNA damage and cellular death. For extracranial xenografts, tirapazamine treatments have shown promise. We therefore incorporated tirapazamine into the synthetic, biodegradable polymer, measured the release, and tested the efficacy both alone and in combination with external beam radiotherapy in the treatment of experimental intracranial human malignant glioma xenografts. The [(poly(bis(p-carboxyphenoxy)-propane) (PCPP):sebacic acid (SA) (PCPP:SA ratio 20:80)] polymer was synthesized. The PCPP:SA polymer and solid tirapazamine were combined to yield proportions of 20% or 30% (wt/wt). Polymer discs (3 x 2 mm) (10 mg) were incubated (PBS, 37 degrees C), and the proportion of the drug released vs. time was recorded. Male nu/nu nude mice were anesthetized and received intracranial injections of 2 x 10(5) U251 human malignant glioma cells. For single intraperitoneal (i.p.) drug and/or external radiation treatments, groups of mice had i.p. 0.3 mmol/kg tirapazamine, 5 Gy cranial irradiation, or combined treatments on day 8 after inoculation. For fractionated drug and radiation treatments, mice had i.p. 0.15 mmol/kg tirapazamine, 5 Gy radiation, or combined treatments on days 8 and 9 after inoculation. For intracranial (i.c.) polymer treatments, mice had craniectomies and intracranial placement of polymer discs at the site of cellular inoculation. The maximally tolerated percentage loading of tirapazamine in the polymer.disc was determined. On day 7 after inoculation, groups of mice had i.c. empty or 3% tirapazamine alone or combined with radiation (5 Gy x 2 doses) or combined with i.p. drug (0.15 mmol/kg x 2 doses on days 8 and 9). Survival was recorded. Polymers showed controlled, protracted in vitro release for over 100 days. The 5 Gy x 1 treatment resulted in improved survival; 28.5 +/- 3.7 days (P = 0.01 vs. controls), while the single i.p. 0.3 mmol/kg tirapazamine treatment, 17.5 +/- 1.9 days (P = NS) and combined treatments; 21.5 +/- 5.0 days (P = NS) were not different. The fractionated treatments: 5 Gy x 2, i.p. 0.15 mmol/kg tirapazamine x 2 and the combined treatments resulted in improved survival: 44.5 +/- 3.9 (P < 0.001), 24.5 +/- 2.3 (P = 0.05) and 50.0 +/- 6.0 (P < 0.001), respectively. Survival after intracranial empty polymer was 16.5 +/- 3.0 days and increased to 31.0 +/- 3.0 (P = 0.003) days when combined with the 5 Gy x 2 treatment. The survival after the polymer bearing 3% tirapazamine alone vs. combined with radiation was not different. The combined 3% tirapazamine polymer, i.p. tirapazamine, and radiation treatments resulted in both early deaths and the highest long-term survivorship. The basis for potential toxicity is discussed. We conclude that implantable biodegradable polymers provide controlled intracranial release for treatment of experimental glioma. For treatment of malignant gliomas, the combination of continuous polymer-mediated delivery and fractionated systemic delivery of tirapazamine with external beam radiotherapy warrants further exploration.
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Affiliation(s)
- X Yuan
- Department of Oncology, Johns Hopkins Oncology Center, Baltimore, Maryland 21205, USA
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Wang X, Doherty GP, Leith MK, Curphey TJ, Begleiter A. Enhanced cytotoxicity of mitomycin C in human tumour cells with inducers of DT-diaphorase. Br J Cancer 1999; 80:1223-30. [PMID: 10376975 PMCID: PMC2362377 DOI: 10.1038/sj.bjc.6690489] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
DT-diaphorase is a two-electron reducing enzyme that activates the bioreductive anti-tumour agent, mitomycin C (MMC). Cell lines having elevated levels of DT-diaphorase are generally more sensitive to MMC. We have shown that DT-diaphorase can be induced in human tumour cells by a number of compounds, including 1,2-dithiole-3-thione. In this study, we investigated whether induction of DT-diaphorase could enhance the cytotoxic activity of MMC in six human tumour cell lines representing four tumour types. DT-diaphorase was induced by many dietary inducers, including propyl gallate, dimethyl maleate, dimethyl fumarate and sulforaphane. The cytotoxicity of MMC was significantly increased in four tumour lines with the increase ranging from 1.4- to threefold. In contrast, MMC activity was not increased in SK-MEL-28 human melanoma cells and AGS human gastric cancer cells, cell lines that have high base levels of DT-diaphorase activity. Toxicity to normal human marrow cells was increased by 50% when MMC was combined with 1,2-dithiole-3-thione, but this increase was small in comparison with the threefold increase in cytotoxicity to tumour cells. This study demonstrates that induction of DT-diaphorase can increase the cytotoxic activity of MMC in human tumour cell lines, and suggests that it may be possible to use non-toxic inducers of DT-diaphorase to enhance the efficacy of bioreductive anti-tumour agents.
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Affiliation(s)
- X Wang
- Manitoba Institute of Cell Biology, Manitoba Cancer Treatment and Research Foundation and Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada
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López de Cerain A, Marín A, Idoate MA, Tuñón MT, Bello J. Carbonyl reductase and NADPH cytochrome P450 reductase activities in human tumoral versus normal tissues. Eur J Cancer 1999; 35:320-4. [PMID: 10448278 DOI: 10.1016/s0959-8049(98)00372-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The use of bioreductive agents in enzyme-directed bioreductive therapy has been proposed to take advantage not only of hypoxia in tumours, but also of the presence of reductases that metabolise such compounds. In this study, we studied the activities of NADPH cytochrome P450 reductase (P450R) and carbonyl reductase (CR) in 17 human lung tumours and 18 human breast tumours, together with the corresponding normal tissues. For lung cancer but not for breast cancer there was a significant difference in the CR activity between normal and tumour tissue. CR activity was increased with respect to the normal tissue between 2-fold and 40-fold indicating heterogeneity in tumour samples. No relationship was found between CR activity and the histological type, tumoral grade or TNM stage of the tumours. Although some variation in P450R activity in tumoral versus normal tissues was found in the majority of the samples studied, no significant differences could be demonstrated.
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Aboagye EO, Dillehay LE, Bhujwalla ZM, Lee DJ. Hypoxic cell cytotoxin tirapazamine induces acute changes in tumor energy metabolism and pH: a 31P magnetic resonance spectroscopy study. RADIATION ONCOLOGY INVESTIGATIONS 1999; 6:249-54. [PMID: 9885940 DOI: 10.1002/(sici)1520-6823(1998)6:6<249::aid-roi1>3.0.co;2-c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tirapazamine is a hypoxic cell cytotoxin in phase II/III trials. To further understand its mechanism of action in vivo, we examined the effect of tirapazamine on tumor energy metabolism and pH. RIF-1 and SCCVII tumors were grown subcutaneously in the flanks of C3H mice. Tumor energy metabolism, expressed as the ratio of inorganic phosphate to nucleotide triphosphate (Pi/NTP), and intracellular pH (pHi), were measured by 31P magnetic resonance spectroscopy (MRS). In RIF-1 and SCCVII tumors, tirapazamine increased the Pi/NTP ratio by 2.6-fold and 3-fold, respectively, within the first hour after an intraperitoneal dose of 0.3 mmol/kg. A corresponding decrease in pHi from 7.05+/-0.07 to 6.48+/-0.06, and 7.21+/-0.09 to 6.45+/-0.02 in RIF-1 and SCCVII tumors, respectively, was observed. The decrease in tumor 31P bioenergetics and pH was reversible, as exemplified by RIF-1 tumors, which showed a further increase in Pi/NTP ratio of 3.5-fold by 5-8 hr, returning to normal range at 24 hr. Corresponding pHi of RIF-1 tumors was 6.88+/-0.05 at 5-8 hr and 7.16+/-0.05 at 24 hr. We concluded that tirapazamine induces acute changes in tumor energy metabolism and pHi. These findings are relevant to the rational selection and optimal timing of coadministered therapy.
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Affiliation(s)
- E O Aboagye
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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