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Aiyappa-Maudsley R, Elsalem L, Ibrahim AIM, Pors K, Martin SG. In vitro radiosensitization of breast cancer with hypoxia-activated prodrugs. J Cell Mol Med 2022; 26:4577-4590. [PMID: 35841287 PMCID: PMC9357624 DOI: 10.1111/jcmm.17486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/25/2022] [Accepted: 07/01/2022] [Indexed: 12/24/2022] Open
Abstract
KP167 is a novel hypoxia‐activated prodrug (HAP), targeting cancer cells via DNA intercalating and alkylating properties. The single agent and radiosensitizing efficacy of KP167 and its parental comparator, AQ4N, were evaluated in 2D and 3D cultures of luminal and triple negative breast cancer (TNBC) cell lines and compared against DNA damage repair inhibitors. 2D normoxic treatment with the DNA repair inhibitors, Olaparib or KU‐55933 caused, as expected, substantial radiosensitization (sensitiser enhancement ratio, SER0.01 of 1.60–3.42). KP167 induced greater radiosensitization in TNBC (SER0.01 2.53 in MDAMB‐231, 2.28 in MDAMB‐468, 4.55 in MDAMB‐436) and luminal spheroids (SER0.01 1.46 in MCF‐7 and 1.76 in T47D cells) compared with AQ4N. Significant radiosensitization was also obtained using KP167 and AQ4N in 2D normoxia. Although hypoxia induced radioresistance, radiosensitization by KP167 was still greater under 2D hypoxia, yielding SER0.01 of 1.56–2.37 compared with AQ4N SER0.01 of 1.13–1.94. Such data show KP167 as a promising single agent and potent radiosensitiser of both normoxic and hypoxic breast cancer cells, with greater efficacy in TNBCs.
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Affiliation(s)
- Radhika Aiyappa-Maudsley
- Nottingham Breast Cancer Research Centre, Biodiscovery Institute, School of Medicine, University of Nottingham, University Park, Nottingham, UK.,Department of Molecular and Clinical Cancer Medicine, University of Liverpool, William Henry Duncan Building, Liverpool, UK
| | - Lina Elsalem
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford, UK.,Jordan University of Science and Technology, Faculty of Medicine, Department of Pharmacology, Irbid, Jordan
| | - Ali I M Ibrahim
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford, UK.,Faculty of Pharmacy, Al-Zaytoonah University of Jordan, Amman, Jordan
| | - Klaus Pors
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | - Stewart G Martin
- Nottingham Breast Cancer Research Centre, Biodiscovery Institute, School of Medicine, University of Nottingham, University Park, Nottingham, UK
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Matsumoto KI, Mitchell JB, Krishna MC. Effects of oxygen challenging to tissue redox and pO 2 status. Free Radic Biol Med 2019; 130:343-347. [PMID: 30391676 PMCID: PMC8202967 DOI: 10.1016/j.freeradbiomed.2018.10.454] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/11/2018] [Accepted: 10/31/2018] [Indexed: 11/23/2022]
Abstract
Nitroxide free radicals can serve as redox-sensitive MRI contrast agents useful to image the redox status of tissue of interest. In this study, the effect of oxygen content in the inspired gas on the kinetics of metabolism of three nitroxides has been evaluated in the muscle and tumor in mice. SCC tumors (approximate size of 1.0 cm3) on the right hind leg of female C3H/Hen MTV- mice were prepared. Three nitroxides, 3-carboxy-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CxP), 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CmP), and 4-hydroxy-tetramethylpiperidine-N-oxyl (TEMPOL), having different lipophilicities were compared using MR redox imaging. T1-mapping of the tissues was obtained using a multi-slice multi-echo (MSME) sequence with several TRs. The three nitroxides showed differences in accumulation and metabolism/clearance in muscle and tumor. The cell impermeable nitroxide CxP displayed kinetic patterns of slow enhancement followed by a slow decline typical of clearance rather than metabolism. The cell permeable CmP on the other hand showed a relatively faster uptake and metabolism with a modestly higher rate of metabolism in the tumor than muscle. The TEMPOL on the other hand displayed a rapid uptake and reduction with a trend of significantly rapid decay rate in tumor tissue, while slightly higher maximum signal intensity and slower decay rate was observed in normal muscle. The reduction rate of TEMPOL in the tumor was significantly enhanced when the breathing gas had 100%-oxygen while it was not significantly different in the muscle. EPR oximetry studies monitoring the oxygen dependent linewidth of TEMPOL showed that the pO2 in the healthy tissue during carbogen breathing significantly increased normal tissue pO2 compared to air breathing whereas breathing 100%-oxygen made normal tissue slight hypoxic. Since TEMPOL is a radioprotector, our studies show that a combination of 100%-oxygen breathing and TEMPOL has a potential to enhance radioprotective effects to normal tissue.
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Affiliation(s)
- Ken-Ichiro Matsumoto
- Quantitative RedOx Sensing Team, Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba-shi, Chiba 263-8555, Japan.
| | - James B Mitchell
- Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1002, USA
| | - Murali C Krishna
- Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1002, USA
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Yamashita T, Kato T, Isogai T, Gu Y, Ma N. Protective Effects of Taurine on the Radiation Exposure Induced Cellular Damages in the Mouse Intestine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1155:443-450. [DOI: 10.1007/978-981-13-8023-5_41] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Monson LA, Nelson NS, Donneys A, Farberg AS, Tchanque-Fossuo CN, Deshpande SS, Buchman SR. Amifostine Treatment Mitigates the Damaging Effects of Radiation on Distraction Osteogenesis in the Murine Mandible. Ann Plast Surg 2017; 77:164-8. [PMID: 27070667 DOI: 10.1097/sap.0000000000000276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
According to the American Society of Clinical Oncology, in 2012, more than 53,000 new cases of head and neck cancers (HNCs) were reported in the United States alone and nearly 12,000 deaths occurred relating to HNC. Although radiotherapy (XRT) has increased survival, the adverse effects can be unrelenting and their management is rarely remedial. Current treatment dictates surgical mandibular reconstruction using free tissue transfer. These complex operations entail extended hospitalizations and attendant complications often lead to delays in initiation of adjuvant therapy, jeopardizing prognosis as well as quality of life. The creation of new bone by distraction osteogenesis (DO) generates a replacement of deficient tissue from local substrate and could have immense potential therapeutic ramifications. Radiotherapy drastically impairs bone healing, precluding its use as a reconstructive method for HNC. We posit that the deleterious effects of XRT on bone formation could be pharmacologically mitigated. To test this hypothesis, we used a rodent model of DO and treated with amifostine, a radioprotectant, to assuage the XRT-induced injury on new bone formation. Amifostine had a profound salutary effect on bone regeneration, allowing the successful implementation of DO as a reconstructive technique. The optimization of bone regeneration in the irradiated mandible has immense potential for translation from the bench to the bedside, providing improved therapeutic options for patients subjected to XRT.
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Affiliation(s)
- Laura A Monson
- From the *Craniofacial Research Laboratory, Plastic Surgery Section, University of Michigan, Ann Arbor, MI; and †Department of Surgery, Plastic Surgery Section, Baylor College of Medicine, Houston, TX
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Liu C, Liu J, Hao Y, Gu Y, Yang Z, Li H, Li R. 6,7,3′,4′-Tetrahydroxyisoflavone improves the survival of whole-body-irradiated mice via restoration of hematopoietic function. Int J Radiat Biol 2017; 93:793-802. [DOI: 10.1080/09553002.2017.1321808] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Cong Liu
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Jing Liu
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Yuhui Hao
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Ying Gu
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Zhangyou Yang
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Hong Li
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Rong Li
- Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
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Das A, Chadha R, Maiti N, Kapoor S. Synthesis of pH sensitive gold nanoparticles for potential application in radiosensitization. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 55:34-41. [DOI: 10.1016/j.msec.2015.05.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 04/16/2015] [Accepted: 05/15/2015] [Indexed: 01/16/2023]
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Chemotherapy for muscle-invasive bladder cancer treated with definitive radiotherapy: persisting uncertainties. ACTA ACUST UNITED AC 2008; 5:444-54. [DOI: 10.1038/ncponc1159] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Accepted: 12/11/2007] [Indexed: 11/09/2022]
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Brix G, Schlicker A, Mier W, Peschke P, Bellemann ME. Biodistribution and pharmacokinetics of the 19F-labeled radiosensitizer 3-aminobenzamide: assessment by 19F MR imaging. Magn Reson Imaging 2005; 23:967-76. [PMID: 16310113 DOI: 10.1016/j.mri.2005.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 09/11/2005] [Indexed: 11/16/2022]
Abstract
3-Aminobenzamide (3-ABA) is a potent radiosensitizer that inhibits the repair of DNA strand breaks. The aim of this study was to monitor the biodistribution and pharmacokinetics of a fluorinated 3-ABA derivative in tumor-bearing rats by magnetic resonance imaging (MRI). To this end, 3-ABA was labeled with fluorine-19 by trifluoroethylation [3-amino-N-2,2,2-trifluoroethylbenzamide (3-ABA-TFE)], which only slightly increased the cytotoxicity of the compound as demonstrated by colony-forming assays. After intraperitoneal injection of 400 mg/kg BW 3-ABA-TFE to nine Copenhagen rats with Dunning prostate adenocarcinoma, (19)F MR images were acquired at a whole-body MR system with a spatial sampling of 10 x 10 x 15 mm(3). While 3-ABA-TFE was observed in all major organs and the muscular system, only a small and heterogeneous signal could be detected in the adenocarcinoma. Serial MR measurements yielded maximum tissue signals about 2 days after 3-ABA-TFE administration. At this time point, the mean muscle-to-liver and tumor-to-liver signal ratio was 0.31+/-0.07 and 0.11+/-0.04, respectively. Application of the (19)F MRI strategy makes it possible to measure the biodistribution and pharmacokinetics of 3-ABA-TFE in individual animals in a longitudinal manner. The results obtained for the prostate adenocarcinoma indicate that delivery of 3-ABA-TFE to solid tumors may be seriously hampered by tumor-specific factors and that the intratumoral uptake of the substance may be lower than in normal tissues. Therefore, the development of effective carrier systems is mandatory to improve tumor-selective delivery.
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Affiliation(s)
- Gunnar Brix
- Research Program 'Innovative Diagnosis and Therapy,' German Cancer Research Center (DKFZ), D-69120 Heidelberg, Germany
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Sigounas G, Sallah S, Sigounas VY. Erythropoietin modulates the anticancer activity of chemotherapeutic drugs in a murine lung cancer model. Cancer Lett 2004; 214:171-9. [PMID: 15363543 DOI: 10.1016/j.canlet.2004.06.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 05/25/2004] [Accepted: 06/01/2004] [Indexed: 12/27/2022]
Abstract
In this study, we assessed the ability of erythropoietin (EPO) to synergize with various chemotherapeutic agents and suppress the growth and metastasis of solid tumors. Animals were inoculated with Lewis lung carcinoma (LLC) cells and treated with EPO alone, the designated chemotherapeutic drug (cisplatin, mitomycin C or cyclophoshamide) alone, or EPO and the drug. Tumor volume was monitored daily. Thirteen days following cell injection, tumor mass was determined. In addition, the number of the metastatic foci in the lungs was determined. Cisplatin alone was capable of inducing a 7-fold decrease in final tumor volume compared to tumor-bearing animals injected with saline. However, when EPO was combined with cisplatin, the animals experienced an 11-fold reduction in final tumor volume compared to saline-injected animals (P<0.001). A 2.5-fold reduction in tumor mass was observed in animals treated with cisplatin, compared to the saline-injected groups. Furthermore, injections of EPO and cisplatin induced a 4-fold reduction in tumor mass (P<0.001). Blood analysis indicated that a significant increase of more than 30% in WBC was found in animals injected concurrently with cisplatin and EPO, as compared to saline-injected mice (P<0.03). When EPO and mitomycin C were injected together, tumor mass was further reduced by 14% compared to that seen in mice treated with mitomycin C alone. However, this difference was not statistically significant. We conclude from this study that EPO can synergize with chemotherapeutic agents to further suppress the growth of tumors. The level of synergism is drug related.
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Affiliation(s)
- George Sigounas
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Hem/Onc Section, Brody Bldg, Rm 3E-102, 600 Moye Blvd, Greenville, NC 27858, USA.
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Jennings MT, Iyengar S. Pharmacotherapy of malignant astrocytomas of children and adults: current strategies and future trends. CNS Drugs 2002; 15:719-43. [PMID: 11580310 DOI: 10.2165/00023210-200115090-00005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
This article reviews the conceptual progression in the pharmacological therapy of malignant astrocytoma (MA) over the past decade, and its future trends. It is a selective rather than an exhaustive inventory of literature citations. The experience of the Brain Tumour Cooperative Group (BTCG) and earlier phase III trials are summarised to place subsequent phase II and I studies of single and combination agent chemotherapy in perspective. The BTCG experience of the 1970s to 1980s may be summarised to indicate that external beam radiotherapy (EBRT) is therapeutic, although not curative, and not further improved upon by altering fractionation schedules, or the addition of radioenhancers. Whole brain and reduced whole brain EBRT with focal boost were comparable regimens. Nitrosourea-based, adjuvant chemotherapy provided a modest improvement in survival among adult patients, which was comparable with that of other single drugs or multidrug regimes. The multiagent schedules, however, had a correspondingly higher toxicity rate. Intra-arterial administration was associated with significant risk, which conferred no therapeutic advantage. The trend of the past decade has been towards multiagent chemotherapy although its benefit cannot be predicted from the classic prognostic factors. Published experience with investigational trials utilising myeloablative chemotherapy with autologous bone marrow or peripheral blood stem cell haemopoietic support, drug delivery enhancement methods and radiosensitisers is critically reviewed. None of these approaches have achieved wide-spread acceptance in the treatment of adult patients with MA. Greater attention is placed on recent 'chemoradiotherapy' trials, which attempt to integrate and maximise the cytoreductive potential of both modalities. This approach holds promise as an effective means to delay or overcome the evolution of tumour resistance, which is probably one of the dominant determinants of prognosis. However, the efficacy of this approach remains unproven. New chemotherapeutic agents as well as biological response modifiers, protein kinase inhibitors, angiogenesis inhibitors and gene therapy are also discussed; their role in the therapeutic armamentarium has not been defined.
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Affiliation(s)
- M T Jennings
- Vanderbilt Ingram Cancer Center, Vanderbilt Medical School, 2100 Pierce Avenue, Nashville, TN 37205-3375, USA
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Silver DF, Piver MS. Effects of recombinant human erythropoietin on the antitumor effect of cisplatin in SCID mice bearing human ovarian cancer: A possible oxygen effect. Gynecol Oncol 1999; 73:280-4. [PMID: 10329047 DOI: 10.1006/gyno.1999.5368] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE Experiments were designed to evaluate the effect of an elevated hematocrit using recombinant human erythropoietin (Epo) on the antitumor response of cisplatin on human ovarian cancer engrafted in mice. METHODS Forty female severe combined immunodeficient (SCID) mice with large human ovarian cancer xenografts implanted on the gonadal fat pad (GFP) and 40 female SCID mice with small subcutaneous (sq) human ovarian cancer xenografts were placed in one of four treatment groups. Group 1 (controls) received phosphate-buffered saline injections. Group 2 (Epo group) received Epo at 20 units three times per week. Group 3 (cisplatin group) received cisplatin at 5 mg/kg/week. Group 4 (Epo + cisplatin group) received Epo and cisplatin as above. Cisplatin was administered on day 0 for mice bearing large GFP tumors and was injected on days 0 and +7 for mice bearing small sq tumors. Epo injections were started on day -15 and continued until the completion of the experiment. Evaluations of the tumor growth, hematocrits, and performance status were made. The experiments were repeated in 24 SCID mice bearing small sq tumor xenografts with similar results. Representative data were reported. RESULTS Among mice bearing large GFP tumors, a tumor growth delay was noted in the groups that received cisplatin with or without Epo compared to controls (P < 0.05). However, significant tumor growth delay could not be reached for mice in the Epo + cisplatin group compared to the cisplatin group (P = 0.07). Among mice bearing small sq tumors, a significant improvement in tumor regression was achieved in the Epo + cisplatin group compared to the cisplatin group (P < 0.05). No difference in tumor growth resulted in the Epo group compared to controls. Epo resulted in a 25-35% increase in the hematocrit in both the Epo group and the Epo + cisplatin group (P < 0.01). Mice in the control and in the Epo groups remained healthy. Mice treated with cisplatin developed objective signs of morbidity; however, performance scores for mice in the Epo + cisplatin group remained lower than scores in the cisplatin group. CONCLUSIONS The data demonstrate a cisplatin-sensitizing effect on human ovarian cancer in SCID mice induced by the pretreatment elevation and maintenance of the hematocrit using Epo. These findings are consistent with an oxygen sensitization of cisplatin. Corroboration of these results may have significant clinical implications for the treatment of solid tumor patients.
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Affiliation(s)
- D F Silver
- Department of Gynecologic Oncology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA
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Cmelak AJ, Cox RS, Adler JR, Fee WE, Goffinet DR. Radiosurgery for skull base malignancies and nasopharyngeal carcinoma. Int J Radiat Oncol Biol Phys 1997; 37:997-1003. [PMID: 9169805 DOI: 10.1016/s0360-3016(97)00111-9] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Patients with skull base lesions present a challenging management problem because of intractable symptoms and limited therapeutic options. In 1989 we began treating selected patients with skull base lesions using linac stereotactic radiosurgery. In this study the efficacy and toxicity of this therapeutic modality is investigated. METHODS AND MATERIALS Forty-seven patients with 59 malignant skull base lesions were treated with linac radiosurgery between 1989 and 1995. Eleven patients were treated for primary nasopharyngeal carcinoma using radiosurgery as a boost (7 Gy-16 Gy, median: 12 Gy) to the nasopharynx after a course of fractionated radiotherapy (64.8-70 Gy) without chemotherapy. Another 37 patients were treated for 48 skull base metastases or local recurrences from primary head and neck cancers. Eight of these patients had 12 locally recurrent nasopharyngeal carcinoma lesions occuring 6-96 months after standard radiotherapy, including one patient with nasopharyngeal carcinoma who developed a regional relapse after radiotherapy with a stereotactic boost. Lesion volumes by CT or MRI ranged from 0 to 51 cc (median: 8 cc). Radiation doses of 7.0 Gy-35.0 Gy (median: 20.0 Gy) were delivered to recurrent lesions, usually as a single fraction. RESULTS All 11 patients who received radiosurgery as a nasopharyngeal boost after standard fractionated radiotherapy remain locally controlled (follow-up: 2-34 months, median: 18). However, one patient required a second radiosurgical treatment for regional relapse outside the initial radiosurgery volume. Thirty-three of 48 (69%) recurrent/metastatic lesions have been locally controlled, including 7 of 12 locally recurrent nasopharyngeal lesions. Follow-up for all patients with recurrent lesions ranged from 1 to 60 months (median: 9 months). Local control did not correlate with lesion size (p = 0.80), histology (p = 0.78), or radiosurgical dose (p = 0.44). Major complications developed after 5 of 59 treatments (8.4%), including three cranial nerve palsies, one CSF leak, and one trismus. Complications were not correlated with radiosurgical volume (p = 0.20), prior skull base irradiation (p = 0.90), or radiosurgery dose > 20 Gy (p = 0.49). CONCLUSION Stereotactic radiosurgery is a reasonable treatment modality for patients with skull base malignancies, including patients with primary and recurrent nasopharyngeal carcinoma. The dose distribution obtained with stereotactic radiosurgery provides better homogeneity than an intracavitary implant when used as a boost for nasopharyngeal lesions, especially lesions which involve areas distant to the nasopharyngeal mucosa.
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Affiliation(s)
- A J Cmelak
- Department of Radiation Oncology, Stanford University Medical Center, CA, USA.
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Langmuir VK, Laderoute KR, Mendonca HL, Sutherland RM, Hei TK, Liu SX, Hall EJ, Naylor MA, Adams GE. Fused pyrazine mono-n-oxides as bioreductive drugs. II Cytotoxicity in human cells and oncogenicity in a rodent transformation assay. Int J Radiat Oncol Biol Phys 1996; 34:79-84. [PMID: 12118568 DOI: 10.1016/0360-3016(95)02077-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To determine what structural moieties of the fused pyrazine mono-N-oxides are determining factors in their in vitro cytotoxicity and oncogenicity. METHODS AND MATERIALS A new series of experimental bioreductive drugs, fused pyrazine mono-N-oxides, was evaluated in vitro for aerobic and hypoxic cytotoxicity in the HT29 human colon adenocarcinoma cell line by using clonogenic assays. The relative oncogenicities of these compounds were also determined in aerobic cultures of C3H 10T1/2 mouse embryo fibroblasts by using a standard transformation assay. RESULTS Removal of the 4-methyl piperazine side chain from the parent compound, RB 90740, reduced the potency of the hypoxic cytotoxin. Reduction of the N-oxide function increased the aerobic cytotoxicity and eliminated most of the hypoxic/aerobic cytotoxic differential. The reduced N-oxide also had significant oncogenicity, consistent with a mechanism of genotoxicity following bioreduction of RB 90740. CONCLUSION This new series of bioreductive compounds may be effective in cancer therapy, particularly the lead compound RB 90740. The oncogenic potential of these compounds is similar to that for other cancer therapies. Further studies should include evaluation of these compounds in vivo and the development of analogs with reduced oncogenic potential and retention of the hypoxic/aerobic cytotoxicity differential.
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Affiliation(s)
- V K Langmuir
- SRI International, Menlo Park, CA 94025-3493, USA
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Brown JM. Hypoxic cell radiosensitizers: the end of an era? Regarding Lee et al., IJROBP 32:567-576; 1995. Int J Radiat Oncol Biol Phys 1995; 32:883-5. [PMID: 7790276 DOI: 10.1016/0360-3016(95)00186-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Activation of AP-1 and of a nuclear redox factor, Ref-1, in the response of HT29 colon cancer cells to hypoxia. Mol Cell Biol 1994. [PMID: 8065332 DOI: 10.1128/mcb.14.9.5997] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many solid tumors contain substantial fractions of hypoxic cells which are relatively resistant to both radiation therapy and certain cytotoxic drugs. We have previously shown that exposure of human HT29 cells to hypoxic conditions results in the overexpression of certain enzymes involved in the detoxication of xenobiotics, including NAD(P)H:(quinone acceptor) oxidoreductase (DT)-diaphorase, and gamma-glutamylcysteine synthetase, the rate-limiting enzyme in glutathione synthesis. This hypoxic effect on DT-diaphorase was shown to involve both transcriptional induction and altered message stability. We have investigated the effects of hypoxia on elements in the promoter region of DT-diaphorase. Electrophoretic mobility shift assays demonstrate the induction of a binding activity to the AP-1 response element of DT-diaphorase. Supershift assays suggest that this binding is due to AP-1 nuclear factors and that members of the jun family are induced to a greater degree than fos by hypoxia. Analysis of the kinetics of transcription factor expression indicates that the expression of c-jun and junD is induced during hypoxic exposure; mRNA levels fall during reoxygenation. Induction of fos on the other hand is not as florid during hypoxia (5-fold) and is most pronounced (17-fold) 24 h after the restoration of an oxic environment. Thus, the hypoxic response of DT-diaphorase expression is mediated in part through AP-1, initially by a jun-related mechanism and then by the involvement of fos. The affinity of transcription factors for the AP-1 binding site depends on the redox state of a cysteine residue located close to the DNA-binding region of both Fos and Jun. A nuclear protein, Ref-1, maintains the reduced state of Fos and Jun and promotes binding to AP-1. Nuclear extracts of HT29 cells exposed to hypoxia show markedly increased Ref-1 protein content. Elevation of ref-1 steady-state mRNA levels occurs as an early event following induction of hypoxia and persists when cells are restored to a normally oxygenated environment. Nuclear run-on analysis demonstrates that induction of transcription is the mechanism of ref-1 mRNA elevation. Electrophoretic mobility shift assays and immunodepletion assays were used to further define the interaction of Ref-1 with specific AP-1-binding proteins under hypoxic conditions. These data demonstrate that the induction of detoxicating enzyme expression in HT29 cells exposed to hypoxia results from the induction of both transactivating factors that bind to the AP-1 element and of redox proteins that enhance their affinity for this element.
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Mazur L, Czyzewska A. Inhibition of the clastogenic effect of cyclophosphamide by WR-2721 in the bone marrow of mice. Mutat Res 1994; 309:219-23. [PMID: 7520979 DOI: 10.1016/0027-5107(94)90095-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The frequency of micronucleated polychromatic erythrocytes in the bone marrow of Swiss mice treated with WR-2721, at a dose of 200 mg/kg or 400 mg/kg body weight, 15 or 30 min prior to cyclophosphamide (CP) administration, at a dose of 200 mg/kg body weight, was determined 24 h after CP treatment. In mice injected with CP, the number of micronuclei in polychromatic erythrocytes was significantly increased in comparison with the controls, and in mice treated with WR-2721 and CP, the frequency of micronucleated polychromatic erythrocytes was distinctly decreased in comparison to those given CP alone. The protective effect of WR-2721 against cyclophosphamide-induced clastogenicity was shown. The effect was dependent on the dose of the thiol agent given, and it was more expressed when WR-2721 was applied at the higher dose, 400 mg/kg body weight. However, the protection by the aminothiol appeared not to depend on the time intervals between WR-2721 and CP administration to the mouse organism.
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Affiliation(s)
- L Mazur
- Department of Animal Physiology, Jagiellonian University, Cracow, Poland
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17
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Yao KS, Xanthoudakis S, Curran T, O'Dwyer PJ. Activation of AP-1 and of a nuclear redox factor, Ref-1, in the response of HT29 colon cancer cells to hypoxia. Mol Cell Biol 1994; 14:5997-6003. [PMID: 8065332 PMCID: PMC359125 DOI: 10.1128/mcb.14.9.5997-6003.1994] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Many solid tumors contain substantial fractions of hypoxic cells which are relatively resistant to both radiation therapy and certain cytotoxic drugs. We have previously shown that exposure of human HT29 cells to hypoxic conditions results in the overexpression of certain enzymes involved in the detoxication of xenobiotics, including NAD(P)H:(quinone acceptor) oxidoreductase (DT)-diaphorase, and gamma-glutamylcysteine synthetase, the rate-limiting enzyme in glutathione synthesis. This hypoxic effect on DT-diaphorase was shown to involve both transcriptional induction and altered message stability. We have investigated the effects of hypoxia on elements in the promoter region of DT-diaphorase. Electrophoretic mobility shift assays demonstrate the induction of a binding activity to the AP-1 response element of DT-diaphorase. Supershift assays suggest that this binding is due to AP-1 nuclear factors and that members of the jun family are induced to a greater degree than fos by hypoxia. Analysis of the kinetics of transcription factor expression indicates that the expression of c-jun and junD is induced during hypoxic exposure; mRNA levels fall during reoxygenation. Induction of fos on the other hand is not as florid during hypoxia (5-fold) and is most pronounced (17-fold) 24 h after the restoration of an oxic environment. Thus, the hypoxic response of DT-diaphorase expression is mediated in part through AP-1, initially by a jun-related mechanism and then by the involvement of fos. The affinity of transcription factors for the AP-1 binding site depends on the redox state of a cysteine residue located close to the DNA-binding region of both Fos and Jun. A nuclear protein, Ref-1, maintains the reduced state of Fos and Jun and promotes binding to AP-1. Nuclear extracts of HT29 cells exposed to hypoxia show markedly increased Ref-1 protein content. Elevation of ref-1 steady-state mRNA levels occurs as an early event following induction of hypoxia and persists when cells are restored to a normally oxygenated environment. Nuclear run-on analysis demonstrates that induction of transcription is the mechanism of ref-1 mRNA elevation. Electrophoretic mobility shift assays and immunodepletion assays were used to further define the interaction of Ref-1 with specific AP-1-binding proteins under hypoxic conditions. These data demonstrate that the induction of detoxicating enzyme expression in HT29 cells exposed to hypoxia results from the induction of both transactivating factors that bind to the AP-1 element and of redox proteins that enhance their affinity for this element.
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Affiliation(s)
- K S Yao
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
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18
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Parrick J, Mehta LK, Hodgkiss RJ. The synthesis of a potential anti-cancer agent containing the caffeine and 1,2,4-benzotriazine moieties. J Heterocycl Chem 1993. [DOI: 10.1002/jhet.5570300205] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Abstract
BACKGROUND Seven patients received stereotaxic radiosurgery for 10 lesions at the base of the skull (BOS) from recurrent head and neck malignant neoplasms. METHODS A radiation dose of 17.5-35.0 Gy was delivered as a single fraction. Follow-up ranged from 1 to 14 months. RESULTS Nine lesions were symptomatic, and the symptoms improved in five and stabilized in four lesions. In addition, a significant radiographic response was observed in 4 of 10 recurrences. Cranial nerve signs developed in two patients, and an area of asymptomatic necrosis developed in one patient in the temporal lobe tip. CONCLUSIONS From their brief experience, the authors conclude that stereotaxic radiosurgery may be a promising treatment in locally controlling recurrent head and neck cancers that involve the BOS.
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Affiliation(s)
- I D Kaplan
- Department of Radiation Oncology, Stanford University School of Medicine, California 94305
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20
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Abstract
The development of effective low-LET radiation therapy for cancer has been hindered by the lack of consistent differential responses to radiation between tumor and normal tissues. One major difference between many solid tumors and the surrounding normal stroma is the presence of hypoxic foci in solid tumors due to the inadequate supply of nutritional needs as a result of the breakdown of microvasculature. Consequently, failure of conventional radiotherapy and local recurrences are in part attributed to the radioresistant hypoxic cell populations, present in the tumor. Local cure/control rates of a tumor can be increased only by an effective increase in the radiation dose. At the same time, an increase in such a dose would damage the oxic normal stroma, more than the hypoxic tumor cells. Hence, specific modification of tumor radiosensitivity by the use of chemical radiosensitizers, in combination with conventional radiotherapy, is an attractive alternative. Many clinicians and radiotherapists are skeptical about the outcome of using radiosensitizers in patients. Nevertheless, a vast amount of information is currently available regarding the first- and second-generation radiosensitizers both in murine and in human tumors. As a result, it is hoped that eventually a radiosensitizing drug would be discovered/synthesized that will overcome the drawbacks so far encountered in their use in the clinic. In this article, the development of chemical radiosensitizers since the early sixties, the basis for their selection, their mechanism(s) of action, and the results obtained with the various groups of radiosensitizers are reviewed.
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Affiliation(s)
- M A Shenoy
- Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Trombay, Bombay, India
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21
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Buc-Calderon P, Roberfroid M. Increase in the survival time of mice exposed to ionizing radiation by a new class of free radical scavengers. EXPERIENTIA 1990; 46:708-10. [PMID: 2164953 DOI: 10.1007/bf01939941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
N-acyl dehydroalanines react with and scavenge mainly superoxide radical (O-2.) and hydroxyl radical (HO.). The ortho-methoxyphenylacetyl dehydroalanine derivative, indexed as AD-20, protects mice against damage resulting from total body X-irradiation, as measured by the increase in their survival time. AD-20 increases the LD50 at 30 days from 6.1 to 7.3 Gy in animals exposed to a wide range of X-rays (6 to 10 Gy). The dose reduction factor (D R F) of AD-20 is 1.20. We postulate that such radioprotective effect may result from its free radical scavenging activity.
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Affiliation(s)
- P Buc-Calderon
- Unité de Biochimie Toxicologique et Cancérologique, Université Catholique de Louvain, Brussels, Belgium
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22
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Phillips TL, Mitchell JB, DeGraff WG, Russo A, Albright N, Rajpal R. Modification of SR 2508 sensitization in hypoxic V79 cells by manipulation of glutathione levels. Int J Radiat Oncol Biol Phys 1989; 16:1335-9. [PMID: 2523886 DOI: 10.1016/0360-3016(89)90310-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This series of experiments employed the hypoxic cell sensitizer SR 2508 in concentrations ranging from 0.1 to 10 mM and V-79 cells irradiated in air or made hypoxic in glass syringes, then irradiated with 15 MV X rays. Using a series of survival curves measured at the various concentrations, K curves relating sensitizer enhancement ratio (SER) to SR 2508 concentration were calculated with normal GSH levels or with depletion of GSH to 0% using 1 mM buthionine sulfoximine (BSO) or elevation to 200% of normal using 1 mM oxothiazolidine carboxylate (OTZ). Survival curves were fitted by computer, allowing calculation of standard errors for the SER values. The depletion of GSH by BSO sensitized hypoxic and aerated cells significantly and caused more than additive enhancement of SR 2508 sensitization in hypoxic cells. Elevation of GSH with OTZ protects cells irradiated in air or hypoxia and reduces the SER obtained with SR 2508. The results further support the importance of GSH levels in influencing sensitization by nitroimidazoles.
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Affiliation(s)
- T L Phillips
- Radiation Oncology Branch, National Cancer Institute
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23
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Bydder PV, Burry AF, Gowland S, Bourne RG, Chapman P, Firth LA, Gray AJ, McIlroy R. A controlled trial of misonidazole in the curative treatment of infiltrating bladder cancer. AUSTRALASIAN RADIOLOGY 1989; 33:8-14. [PMID: 2653300 DOI: 10.1111/j.1440-1673.1989.tb03227.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Between 1980 and 1983 a total of 89 patients with infiltrating transitional cell carcinoma of the bladder were entered in a multi centre randomised controlled clinical trial with either misonidazole or placebo added to the first 40.00 Gy of radiotherapy. Depending on their referring clinican, patients then completed treatment with either further radiotherapy to a radical dose, or surgery four weeks later. All patients have been followed up for a minimum of three years, and no significant difference has been found in local control, survival, or pathological downstaging of the tumour. The neurotoxicity was considerable, with 43% of patients receiving misonidazole developing a peripheral neuropathy, starting five weeks on average after beginning treatment, and with a mean duration of 27 months. Eighty per cent of patients affected still had peripheral neuropathy at three years or their prior death. There is a suggestion that alcohol may predispose to the neuropathy. This study failed to show any benefit of misonidazole in tumour control and produced unacceptably high levels of toxicity.
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24
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Affiliation(s)
- D J Grdina
- Biological and Environmental Research Division, Argonne National Laboratory, Illinois 60439
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25
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Floersheim GL, Chiodetti N, Bieri A. Differential radioprotection of bone marrow and tumour cells by zinc aspartate. Br J Radiol 1988; 61:501-8. [PMID: 3370431 DOI: 10.1259/0007-1285-61-726-501] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The radioprotector zinc aspartate did not inhibit the radiotherapeutic effect of gamma rays on human tumours grown as xenografts in immunosuppressed mice, while aminothiol radioprotectors afforded a slight inhibition. On the other hand, zinc aspartate significantly reduced the fall in the haematocrit and numbers of thrombocytes, erythrocytes and leucocytes caused by irradiation, indicating a sparing effect on bone marrow precursors of peripheral blood cells. This differential protection of neoplastic and normal cells may be of considerable benefit in clinical cancer radiotherapy, provided that zinc aspartate is better tolerated and has a more favourable therapeutic index in humans than aminothiol radioprotectors.
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Affiliation(s)
- G L Floersheim
- Department of Surgery, Kantonsspital, Basel, Switzerland
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26
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Sigdestad CP, Guilford W, Perrin J, Grdina DJ. Cell cycle redistribution of cultured cells after treatment with chemical radiation protectors. CELL AND TISSUE KINETICS 1988; 21:193-200. [PMID: 3224366 DOI: 10.1111/j.1365-2184.1988.tb00857.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effect of two radioprotective agents (WR-1065 and WR-151326) was tested for their ability to modify cell cycle progression. Each protector was administered at a concentration of 4 mmol to exponentially growing cultures of V79 cells for periods of time up to 3 h. Under these conditions no cell toxicity was observed. At selected times up to and after removal of the protector, aliquots of cells were removed, counted and fixed in cold 70% ethanol. The cells were stained with DAPI in a 0.1% citrate solution and DNA histograms were obtained using a PARTEC PAS-II flow cytometer. The coefficient of variation of the G1 peaks obtained for unperturbed cell samples routinely ranged from 1.5 to 2.5%. During exposure, both radioprotectors effectively perturbed cell cycle progression, as characterized by a build-up of cells in S and G2 phases. After the protectors were removed, cells began to redistribute throughout the cell cycle. Twelve hours were required before cells exposed to WR-1065 approached levels commensurable with controls. In contrast, cells treated with WR-151236 required about 24 h to redistribute to control levels. These data demonstrate that different thiol-containing radioprotective compounds can differentially affect the progression and redistribution of exposed cells.
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Affiliation(s)
- C P Sigdestad
- Radiation Oncology Department, J.G. Brown Cancer Center, University of Louisville School of Medicine, KY 40292
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27
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Affiliation(s)
- E Finkelstein
- Radiation Oncology Branch, National Cancer Institute, Bethesda, MD 20892
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28
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Henry Y, Guissani A, Hickel B. Radicals of nitroimidazole derivatives: pH dependence of rates of formation and decay related to acid-base equilibria. INTERNATIONAL JOURNAL OF RADIATION BIOLOGY AND RELATED STUDIES IN PHYSICS, CHEMISTRY, AND MEDICINE 1987; 51:797-809. [PMID: 3496290 DOI: 10.1080/09553008714551091] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Three analogous 5-nitroimidazoles, having radiosensitizing and cytotoxic properties, have been studied by pulse-radiolysis in N2O-saturated aqueous formate solutions. Rates of formation of the radicals ImNO2-. are found to have little pH dependence. Decay of the radicals always follows second-order kinetics. The observed rates of decay decrease by three to four orders of magnitude over the pH range 0-12. A pK at 2.3 has been observed kinetically for metronidazole. The pK assigned to the radical couple (ImH)NO2H./(ImH)-NO2-., or alternatively (ImH2+)-NO2-./(ImH)-NO2-., varies from 4.7 to 6.1, depending on the substituents on the imidazole ring. Intrinsic second-order rate constants for decay of the acidic form of the radical, of the anionic form and of the mixed reactions were determined. While the anionic radical reacts slowly with itself, both the acidic radical self-reaction and the mixed reaction proceed at fast rates. The implications of these chemical properties to the mechanisms of radiosensitization and cytotoxicity of the nitroaryl compounds are briefly discussed.
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29
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Leibel S, Bauer M, Wasserman T, Marcial V, Rotman M, Hornback N, Cooper J, Gillespie B, Pakuris E, Conner N. Radiotherapy with or without misonidazole for patients with stage IIIB or stage IVA squamous cell carcinoma of the uterine cervix: preliminary report of a Radiation Therapy Oncology Group randomized trial. Int J Radiat Oncol Biol Phys 1987; 13:541-9. [PMID: 3104249 DOI: 10.1016/0360-3016(87)90069-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Between August 1980 and November 1984, 119 patients with FIGO Stage IIIB or IVA squamous cell carcinoma of the uterine cervix were randomized to receive radiation therapy (4600 cGy pelvis plus 1000 cGy parametrial boost) followed by intracavitary or external boost to the primary with or without misonidazole (MISO) (400 mg/m2 daily 2 to 4 hours prior to radiation therapy). Patients in the two treatment groups were evenly distributed with respect to stratification variables including stage, Karnofsky Performance score, and positivity of para-aortic nodes. Eighty-nine percent of patients had Stage IIIB disease and 88% had a Karnofsky score of 80 or better. Seventy-five percent of patients treated with radiation therapy alone and 79% of patients treated with radiation therapy plus MISO received a boost via intracavitary application. Life threatening (Grade 4) complications occurred in 5 patients receiving radiation therapy alone and one patient receiving radiation therapy plus MISO. MISO toxicity (Grade 3) was limited to severe nausea and vomiting in two patients. With 119 evaluable patients and a median follow-up of 33 months, 64% of patients receiving radiation therapy alone are alive at 18 months compared with 54% for patients assigned to radiation therapy plus MISO. The median survival for patients treated with radiation therapy alone and radiation therapy plus MISO was 1.9 years and 1.6 respectively. At this point in the study the difference in survival is inconsistent with the hypothesis of an improvement associated with MISO. There have been 23 deaths among the 49 patients treated with radiation therapy plus MISO who have been followed for at least 18 months compared with 17 deaths in 48 patients treated with radiation therapy alone. The chance of observing this number of deaths with radiation therapy plus MISO if the addition of MISO improves survival by 10 to 20% is 0.003 and less than 0.001, respectively. The addition of MISO to radiation failed to improve survival for these patients. The results cannot be explained by an uncharacteristically high survival on the radiation therapy alone arm or by an imbalance in the distribution of prognostic factors. Local-regional control remains a problem in the management of patients with advanced cervical carcinoma. More effective and less toxic radiosensitizing agents are needed.
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30
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Marcial VA. Ninth annual del Regato lecture: optimal multidisciplinary management of head and neck cancer. Int J Radiat Oncol Biol Phys 1987; 13:393-401. [PMID: 3549644 DOI: 10.1016/0360-3016(87)90014-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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31
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Phillips TL, Mitchell JB, de Graff W, Russo A, Glatstein E. Variation in sensitizing efficiency for SR 2508 in human cells dependent on glutathione content. Int J Radiat Oncol Biol Phys 1986; 12:1627-35. [PMID: 2944860 DOI: 10.1016/0360-3016(86)90289-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The observation by several authors and ourselves that manipulation of glutathione (GSH) levels in cultured cells would change the relative sensitization of hypoxic cells by nitroimidazole sensitizers led to the hypothesis that natural variation in GSH level could influence the sensitizer enhancement ratio (SER). Since many human tumor cell lines have shown high GSH levels, the A549 lung line, the HeLa line and a skin fibroblast line, the AG1522, were studied in monolayer culture in glass flasks. The GSH levels (nmol/mg protein) measured were 324 for A549, 103 for HeLa, and 32 for 1522 cells. For V-79 cells the level was 25 nmol/mg. In control experiments there was no effect of up to 10 mM SR 2508 in air but BSO (D,L-buthionine-S-R-sulfoximine) treatment modestly sensitized the A549 in air and nitrogen. Calculation of SER values at 1% survival revealed very little sensitization at 0.1, 0.5, and 1.0 mM SR 2508 for A549 cells (SER not significantly different than 1). At 5 mM the SER was 1.5 and at 10 mM 1.65. In contrast, the SER for fibroblasts was 1.65 at 0.5 mM and 2.2 at 1.0 mM SR 2508. The results for HeLa were intermediate, 1.25 and 1.45 at the same concentrations. Thus, the SER relates to the GSH levels in the cells. Treatment with BSO increased the sensitization of A549 to a level similar to that seen for AG1522 at 0.5 and 1.0 mM. These findings could explain the negative results of some sensitizer clinical trials.
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32
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Horsman MR, Brown DM, Lemmon MJ, Brown JM, Lee WW. Preferential tumor radiosensitization by analogs of nicotinamide and benzamide. Int J Radiat Oncol Biol Phys 1986; 12:1307-10. [PMID: 2944859 DOI: 10.1016/0360-3016(86)90160-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of a range of different analogs of nicotinamide and benzamide on the X ray response of the EMT-6 tumor in vivo was investigated. Using an in vivo/in vitro survival assay, sensitization was seen at a dose of 2 mmole/kg for all but one of the analogs tested. The enhancement ratios (ER's) ranged from 1.0 to 1.5. Of particular interest were nicotinamide and SR-4350 which gave large ER's (1.5 and 1.4 respectively) at doses which were only about 12% of the LD50 values. In one normal tissue studied (skin reaction) a large single dose of nicotinamide (8 mmole/kg) only gave an ER of 1.1. These results will be discussed with reference to the mechanisms involved and the clinical implications.
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33
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34
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Mitchell JB, Phillips TL, DeGraff W, Carmichael J, Rajpal RK, Russo A. The relationship of SR-2508 sensitizer enhancement ratio to cellular glutathione levels in human tumor cell lines. Int J Radiat Oncol Biol Phys 1986; 12:1143-6. [PMID: 2943712 DOI: 10.1016/0360-3016(86)90245-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have recently demonstrated that intracellular elevation of glutathione (GSH) by oxothiazolidine 4-carboxylate lessens SR-2508 hypoxic cell radiosensitization in Chinese hamster cells. This observation, coupled with the fact that GSH depletion potentiates SR-2508 hypoxic radiosensitization, prompted a study of human tumor cell lines whose inherent GSH levels are high compared to normal human cell lines or rodent cell lines. Sensitizer enhancement ratios (SER) for a range of SR-2508 concentrations were determined for human tumor cell lines varying in inherent GSH levels. The SER (at the 1% survival level) for 1 mM SR-2508 was found to decrease as the inherent intracellular GSH level increased, particularly for clinically relevant SR-2508 concentrations. All human tumor cell lines studied yielded lower SER values than Chinese hamster V79 cells over the SR-2508 concentrations studied. GSH depletion by buthionine sulfoximine (BSO) of a human tumor line (A549) particularly high in GSH resulted in potentiation of SR-2508 effects. Maximal sensitization occurred when extremely low GSH levels were attained; however, enhancement was observed for a drop of only 30% in GSH levels. Should these high GSH levels seen in human tumor cell lines also apply to clonogenic or potentially clonogenic cells in human tumors in vivo, these findings might explain, in part, the negative results of some human nitroimidazole clinical trials.
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35
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Himmel PD, Hassett JM. Radiation-induced chronic arterial injury. SEMINARS IN SURGICAL ONCOLOGY 1986; 2:225-47. [PMID: 3330279 DOI: 10.1002/ssu.2980020405] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Acute arterial disruption associated with infection, previous irradiation, and the postoperative state is a well-described entity. The recognition of a chronic form of radiation-induced arterial injury presenting years after therapeutic doses of radiation is less well appreciated. This paper summarizes the vital data obtained by reviewing the literature concerning 162 cases of arterial injury associated with prior radiotherapy. The vessels involved include coronary arteries, the aorta, renal arteries, the extra- and intracranial circulation, the ilio-femoral system, and the upper extremity arteries. A review of the histologic findings, the studies regarding pathogenesis, and the morphology of the lesions found in these 162 patients suggests a disease distinct from the atherosclerotic process.
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Affiliation(s)
- P D Himmel
- Department of Surgery, State University of New York at Buffalo
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