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Allen CH, Skillings R, Ahmed D, Sanchez SC, Altwasser K, Hilan G, Willmore WG, Chauhan V, Cassol E, Murugkar S. Investigating ionizing radiation-induced changes in breast cancer cells using stimulated Raman scattering microscopy. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:076501. [PMID: 37441447 PMCID: PMC10335321 DOI: 10.1117/1.jbo.28.7.076501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/21/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023]
Abstract
Significance Altered lipid metabolism of cancer cells has been implicated in increased radiation resistance. A better understanding of this phenomenon may lead to improved radiation treatment planning. Stimulated Raman scattering (SRS) microscopy enables label-free and quantitative imaging of cellular lipids but has never been applied in this domain. Aim We sought to investigate the radiobiological response in human breast cancer MCF7 cells using SRS microscopy, focusing on how radiation affects lipid droplet (LD) distribution and cellular morphology. Approach MCF7 breast cancer cells were exposed to either 0 or 30 Gy (X-ray) ionizing radiation and imaged using a spectrally focused SRS microscope every 24 hrs over a 72-hr time period. Images were analyzed to quantify changes in LD area per cell, lipid and protein content per cell, and cellular morphology. Cell viability and confluency were measured using a live cell imaging system while radiation-induced lipid peroxidation was assessed using BODIPY C11 staining and flow cytometry. Results The LD area per cell and total lipid and protein intensities per cell were found to increase significantly for irradiated cells compared to control cells from 48 to 72 hrs post irradiation. Increased cell size, vacuole formation, and multinucleation were observed as well. No significant cell death was observed due to irradiation, but lipid peroxidation was found to be greater in the irradiated cells than control cells at 72 hrs. Conclusions This pilot study demonstrates the potential of SRS imaging for investigating ionizing radiation-induced changes in cancer cells without the use of fluorescent labels.
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Affiliation(s)
- Christian Harry Allen
- Carleton University, Department of Physics, Ottawa, Ontario, Canada
- Carleton University, Ottawa-Carleton Institute for Biomedical Engineering, Ottawa, Ontario, Canada
| | - Robyn Skillings
- Carleton University, Department of Health Sciences, Ottawa, Ontario, Canada
| | - Duale Ahmed
- Carleton University, Department of Health Sciences, Ottawa, Ontario, Canada
| | - Sarita Cuadros Sanchez
- Health Canada, Consumer and Clinical Radiation Protection Bureau, Ottawa, Ontario, Canada
| | - Kaitlyn Altwasser
- Health Canada, Consumer and Clinical Radiation Protection Bureau, Ottawa, Ontario, Canada
| | - George Hilan
- Carleton University, Institute of Biochemistry, Departments of Biology and Chemistry, Ottawa, Canada
| | - William G. Willmore
- Carleton University, Institute of Biochemistry, Departments of Biology and Chemistry, Ottawa, Canada
| | - Vinita Chauhan
- Health Canada, Consumer and Clinical Radiation Protection Bureau, Ottawa, Ontario, Canada
| | - Edana Cassol
- Carleton University, Department of Health Sciences, Ottawa, Ontario, Canada
| | - Sangeeta Murugkar
- Carleton University, Department of Physics, Ottawa, Ontario, Canada
- Carleton University, Ottawa-Carleton Institute for Biomedical Engineering, Ottawa, Ontario, Canada
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2
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Rangsrikitphoti P, Marquez-Garban DC, Pietras RJ, McGowan E, Boonyaratanakornkit V. Sex steroid hormones and DNA repair regulation: Implications on cancer treatment responses. J Steroid Biochem Mol Biol 2023; 227:106230. [PMID: 36450315 DOI: 10.1016/j.jsbmb.2022.106230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022]
Abstract
The role of sex steroid hormones (SSHs) has been shown to modulate cancer cytotoxic treatment sensitivity. Dysregulation of DNA repair associated with genomic instability, abnormal cell survival and not only promotes cancer progression but also resistance to cancer treatment. The three major SSHs, androgen, estrogen, and progesterone, have been shown to interact with several essential DNA repair components. The presence of androgens directly regulates key molecules in DNA double-strand break (DSB) repair. Estrogen can promote cell proliferation and DNA repair, allowing cancer cells to tolerate chemotherapy and radiotherapy. Information on the role of progesterone in DNA repair is limited: progesterone interaction with some DNA repair components has been identified, but the biological significance is still unknown. Here, we review the roles of how each SSH affects DNA repair regulation and modulates response to genotoxic therapies and discuss future research that can be beneficial when combining SSHs with cancer therapy. We also provide preliminary analysis from publicly available databases defining the link between progesterone/PR and DDRs & DNA repair regulation that plausibly contribute to chemotherapy response and breast cancer patient survival.
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Affiliation(s)
- Pattarasiri Rangsrikitphoti
- Graduate Program in Clinical Biochemistry and Molecular Medicine and Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Diana C Marquez-Garban
- UCLA Jonsson Comprehensive Cancer and Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Richard J Pietras
- UCLA Jonsson Comprehensive Cancer and Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Eileen McGowan
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Viroj Boonyaratanakornkit
- Graduate Program in Clinical Biochemistry and Molecular Medicine and Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand; Age-related Inflammation and Degeneration Research Unit, Chulalongkorn University, Bangkok 10330, Thailand.
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Sutton TL, Patel R, Behrens S, Schwantes I, Fewel C, Gardiner SK, Johnson N, Garreau JR. Delayed adjuvant endocrine therapy is associated with decreased recurrence-free survival following neoadjuvant chemotherapy for breast cancer. Am J Surg 2023; 225:861-865. [PMID: 36858865 DOI: 10.1016/j.amjsurg.2023.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 01/12/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023]
Abstract
BACKGROUND In hormone receptor-positive breast cancer (HRPBC), endocrine therapy is often initiated after adjuvant radiotherapy given concerns of radiation fibrosis. No studies have investigated how this may impact outcomes in high-risk patients undergoing neoadjuvant chemotherapy (NAC). METHODS Females with nonmetastatic HRPBC receiving NAC from 2011 to 2017 were identified from our multi-institutional database. Interval from surgery to endocrine therapy (ISET) was calculated in weeks. Recurrence-free survival (RFS) and overall survival (OS) were evaluated with Kaplan-Meier and Cox proportional hazards modeling. RESULTS Of 280 patients, 179 (64%) received adjuvant radiotherapy; all deaths (n = 25) and 90% (n = 27) of recurrences occurred in this group, which was the focus of subsequent analysis. Median follow-up was 49 months. Recurrences were predominantly distant metastases (n = 21, 81%). Median ISET was 12 weeks (range 0-55 weeks). On multivariable analysis, ISET >14 weeks was independently associated with worse RFS (HR 3.20, 95% C.I. 1.22-8.40, P = 0.02) but not OS (HR 2.15, 95% C.I. 0.75-6.15, P = 0.15). CONCLUSION In patients with HRPBC treated with NAC and adjuvant radiation, increasing ISET is associated with adverse oncologic outcomes.
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Affiliation(s)
- Thomas L Sutton
- Oregon Health & Science University, Department of Surgery, Portland, OR, 97239, USA
| | - Ranish Patel
- Oregon Health & Science University, Department of Surgery, Portland, OR, 97239, USA
| | - Shay Behrens
- Oregon Health & Science University, Department of Surgery, Portland, OR, 97239, USA
| | - Issac Schwantes
- Oregon Health & Science University, Department of Surgery, Portland, OR, 97239, USA
| | - Connor Fewel
- College of Osteopathic Medicine of the Pacific-Northwest, Lebanon, OR, 97355, USA
| | - Stuart K Gardiner
- Devers Eye Institute, Legacy Research Institute, Portland, OR, 97232, USA
| | - Nathalie Johnson
- Legacy Cancer Institute, Legacy Medical Group Surgical Oncology, Portland, OR, 97227, USA
| | - Jennifer R Garreau
- Legacy Cancer Institute, Legacy Medical Group Surgical Oncology, Portland, OR, 97227, USA.
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4
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Rauniyar S, Pansare K, Sharda A, Singh SR, Saha P, Chilakapati MK, Gupta S. Raman Spectroscopy Revealed Cell Passage-Dependent Distinct Biochemical Alterations in Radiation-Resistant Breast Cancer Cells. ACS OMEGA 2023; 8:5522-5532. [PMID: 36816694 PMCID: PMC9933476 DOI: 10.1021/acsomega.2c06787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
Recapitulating radioresistant cell features in pertinent cell line models is essential for deciphering fundamental cellular mechanisms. The limited understanding of passage and cell cycle phases on radioresistant cells revived post-cryopreservation led us to investigate the effect of sub-culturing in parental and radioresistant MCF-7 cells. In this study, the radioresistant cells showed high-intensity nucleic acid and cytochrome bands, which are potentially a radiation-induced spectral marker. Raman spectroscopy data showed dynamic biochemical alterations in revived radioresistant G2/M synchronized cells at early cell passages 1 and 3 with stabilization at a latter cell passage, 5. The study highlights the importance of cell passaging and cell cycle phases in potentially changing the biochemical parameters during in vitro experiments after the revival of radioresistant cells post-cryopreservation.
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Affiliation(s)
- Sukanya Rauniyar
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
- Training
School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, Maharashtra 400085, India
| | - Kshama Pansare
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
| | - Asmita Sharda
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
- Training
School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, Maharashtra 400085, India
| | - Saurav Raj Singh
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
| | - Panchali Saha
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
- Training
School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, Maharashtra 400085, India
| | - Murali Krishna Chilakapati
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
- Training
School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, Maharashtra 400085, India
| | - Sanjay Gupta
- Advanced
Centre for Treatment, Research, and Education in Cancer, Tata Memorial
Centre, Cancer Research Institute, Kharghar, Navi Mumbai, Maharashtra 410210, India
- Training
School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, Maharashtra 400085, India
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5
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Kang M, Pandit N, Kim AY, Cho SJ, Kwon YJ, Ahn J, Lee KM, Wu S, Oh JS, Jung KY, Kim JS. PCW-1001, a Novel Pyrazole Derivative, Exerts Antitumor and Radio-Sensitizing Activities in Breast Cancer. Front Oncol 2022; 12:835833. [PMID: 35425705 PMCID: PMC9002139 DOI: 10.3389/fonc.2022.835833] [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: 12/14/2021] [Accepted: 02/25/2022] [Indexed: 11/13/2022] Open
Abstract
As pyrazole and its derivatives have a wide range of biological activities, including anticancer activity, the design of novel pyrazole derivatives has emerged as an important research field. This study describes a novel pyrazole derivative that exerts antitumor and radiosensitizing activities in breast cancer both in vitro and in vivo. We synthesized a novel pyrazole compound N,N-dimethyl-N’-(3-(1-(4-(trifluoromethyl)phenyl)-1H-pyrazol-4-yl)phenyl)azanesulfonamide (PCW-1001) and showed that it inhibited several oncogenic properties of breast cancer both in vitro and in vivo. PCW-1001 induced apoptosis in several breast cancer cell lines. Transcriptome analysis of PCW-1001-treated cells showed that it regulates genes involved in the DNA damage response, suggesting its potential use in radiotherapy. Indeed, PCW-1001 enhanced the radiation sensitivity of breast cancer cells by modulating the expression of DNA damage response genes. Therefore, our data describe a novel pyrazole compound, PCW-1001, with antitumor and radiosensitizer activities in breast cancer.
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Affiliation(s)
- Minsung Kang
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Navin Pandit
- Department of Medicinal Chemistry and Pharmacology, University of Science & Technology, Daejeon, South Korea
| | - Ah-Young Kim
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Suk Joon Cho
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Young-Ju Kwon
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea.,Radiological and Medico-Oncological Sciences, University of Science and Technology, Seoul, South Korea
| | - Jiyeon Ahn
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Kyu Myung Lee
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Sangwook Wu
- Research & Development (R&D) Center, Pharmcadd, Busan, South Korea
| | - Jeong Su Oh
- Department of Integrative Biotechnology, Sungkyunkwan University, Suwon, South Korea
| | - Kwan-Young Jung
- Department of Medicinal Chemistry and Pharmacology, University of Science & Technology, Daejeon, South Korea.,Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Jae-Sung Kim
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea.,Radiological and Medico-Oncological Sciences, University of Science and Technology, Seoul, South Korea
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6
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Upadhyay R, Pandey R, Nand Sharma D, Gupta S, Parambath HK, Nair O, Pandey RM, Kumar Julka P, Rath GK. Concurrent or sequential hormonal therapy in era of hypofractionation in early breast cancer: A single‐institution prospective study. Breast J 2020; 26:1885-1887. [DOI: 10.1111/tbj.13825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/07/2020] [Accepted: 03/10/2020] [Indexed: 11/30/2022]
Affiliation(s)
| | - Rambha Pandey
- Department of Radiation Oncology AIIMS New Delhi India
| | | | - Subhash Gupta
- Department of Radiation Oncology AIIMS New Delhi India
| | | | - Omana Nair
- Department of Radiation Oncology AIIMS New Delhi India
| | | | | | - Goura K. Rath
- Department of Radiation Oncology AIIMS New Delhi India
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7
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Physician Survey of Timing of Adjuvant Endocrine Therapy Relative to Radiotherapy in Early Stage Breast Cancer Patients. Clin Breast Cancer 2019; 19:e40-e47. [DOI: 10.1016/j.clbc.2018.08.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/04/2018] [Accepted: 08/27/2018] [Indexed: 01/02/2023]
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8
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McGee SF, Mazzarello S, Caudrelier JM, Lima MAG, Hutton B, Sienkiewicz M, Stober C, Fernandes R, Ibrahim MFK, Vandermeer L, Hilton J, Shorr R, Fergusson D, Clemons M. Optimal sequence of adjuvant endocrine and radiation therapy in early-stage breast cancer - A systematic review. Cancer Treat Rev 2018; 69:132-142. [PMID: 30014951 DOI: 10.1016/j.ctrv.2018.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 01/02/2023]
Abstract
IMPORTANCE Clinical equipoise exists around the optimal time to start adjuvant endocrine therapy in patients who will receive post-operative radiotherapy for breast cancer. Concerns continue to exist regarding potential reduced efficacy, or increased toxicity, when radiation, and endocrine therapy are administered concurrently. OBJECTIVE To perform a systematic review of studies comparing outcomes between sequential and concurrent adjuvant radiation and endocrine therapy in early-stage breast cancer. All modalities of radiation therapy were considered, and endocrine therapy could be either tamoxifen or an aromatase inhibitor. Outcomes of interest included; local, regional or distant recurrence, overall survival and treatment-related toxicities. EVIDENCE REVIEWED PubMed, Ovid Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from 1946 to December 2017. Two reviewers independently assessed each citation using the criteria outlined above. Study quality was assessed using the Cochrane Collaboration's tool for prospective studies, and the Newcastle-Ottawa scale for retrospective studies. FINDINGS Of 2137 unique citations identified, 13 met eligibility criteria. Eleven were unique studies (7569 patients), while 2 of the studies were updated analyses of previous studies. Studies evaluated the timing of adjuvant radiation, and tamoxifen (5 studies, 1550 patients), or aromatase inhibitors (6 studies, 6019 patients). We identified 1 complete randomized clinical trial (150 patients), and 5 retrospective studies (1580 patients), in addition to conference abstracts (5 studies, 5839 patients). Overall, none of the studies showed a significant difference in efficacy, or toxicity, with concurrent versus sequential treatment. However, given the significant heterogeneity of the study populations, it was not possible to conduct a meta-analysis. CONCLUSIONS AND RELEVANCE In the absence of high quality data, adequately powered randomized trials are required to answer this important clinical question.
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Affiliation(s)
- S F McGee
- Department of Medicine and Division of Medical Oncology, University of Ottawa, Ottawa, ON, Canada
| | - S Mazzarello
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - J M Caudrelier
- Department of Radiation Medicine, The Ottawa Hospital Cancer Centre, Ottawa, ON, Canada
| | - M A G Lima
- Instituto do Câncer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - B Hutton
- Clinical Epidemiology Department, The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - M Sienkiewicz
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - C Stober
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - R Fernandes
- Division of Medical Oncology, Department of Oncology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - M F K Ibrahim
- Department of Medicine and Division of Medical Oncology, University of Ottawa, Ottawa, ON, Canada
| | - L Vandermeer
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - J Hilton
- Department of Medicine and Division of Medical Oncology, University of Ottawa, Ottawa, ON, Canada; The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - R Shorr
- The Ottawa Hospital, Ottawa, ON, Canada
| | - D Fergusson
- Clinical Epidemiology Department, The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - M Clemons
- Department of Medicine and Division of Medical Oncology, University of Ottawa, Ottawa, ON, Canada; The Ottawa Hospital Research Institute, Ottawa, ON, Canada.
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9
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Rong C, Meinert ÉFRC, Hess J. Estrogen Receptor Signaling in Radiotherapy: From Molecular Mechanisms to Clinical Studies. Int J Mol Sci 2018; 19:ijms19030713. [PMID: 29498642 PMCID: PMC5877574 DOI: 10.3390/ijms19030713] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/02/2018] [Accepted: 02/26/2018] [Indexed: 12/11/2022] Open
Abstract
Numerous studies have established a proof of concept that abnormal expression and function of estrogen receptors (ER) are crucial processes in initiation and development of hormone-related cancers and also affect the efficacy of anti-cancer therapy. Radiotherapy has been applied as one of the most common and potent therapeutic strategies, which is synergistic with surgical excision, chemotherapy and targeted therapy for treating malignant tumors. However, the impact of ionizing radiation on ER expression and ER-related signaling in cancer tissue, as well as the interaction between endocrine and irradiation therapy remains largely elusive. This review will discuss recent findings on ER and ER-related signaling, which are relevant for cancer radiotherapy. In addition, we will summarize pre-clinical and clinical studies that evaluate the consequences of anti-estrogen and irradiation therapy in cancer, including emerging studies on head and neck cancer, which might improve the understanding and development of novel therapeutic strategies for estrogen-related cancers.
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Affiliation(s)
- Chao Rong
- Section Experimental and Translational Head and Neck Oncology, Department of Otolaryngology, Head and Neck Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany.
| | - Étienne Fasolt Richard Corvin Meinert
- Section Experimental and Translational Head and Neck Oncology, Department of Otolaryngology, Head and Neck Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany.
- Research Group Molecular Mechanisms of Head and Neck Tumors, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
| | - Jochen Hess
- Section Experimental and Translational Head and Neck Oncology, Department of Otolaryngology, Head and Neck Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany.
- Research Group Molecular Mechanisms of Head and Neck Tumors, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
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Mackenzie LS. Thyroid Hormone Receptor Antagonists: From Environmental Pollution to Novel Small Molecules. VITAMINS AND HORMONES 2018; 106:147-162. [DOI: 10.1016/bs.vh.2017.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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11
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Cecchini MJ, Yu E, Yaremko BP, Boldt RG, Potvin K, Sexton T, D'Souza D, Brackstone M, Lock M. A Single Institution Consensus on the Use of Sequential or Concurrent Hormonal Therapy for Breast Cancer Patients Receiving Radiation Therapy. Cureus 2016; 8:e555. [PMID: 27182469 PMCID: PMC4858442 DOI: 10.7759/cureus.555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND AND OBJECTIVES For hormone-sensitive breast cancers, treatment with breast-conserving surgery, tamoxifen, or aromatase inhibitors, along with adjuvant radiation, is the mainstay of therapy. The ideal timing of hormonal and radiation treatment is not well defined, and there is a significant degree of practice variability between concurrent and sequential treatment regimes. This variability can cause confusion amongst the clinical team resulting in contradictory recommendations, loss of patient trust, and the potential for missed initiation of hormonal therapy. METHODS To address this question, a systematic review of the literature was conducted and presented to the breast cancer multidisciplinary team at the London Regional Cancer Center. A three-round modified Delphi method was used to obtain a consensus on a series of a priori determined statements. RESULTS With the currently available evidence, the consensus was that hormonal therapy should be given sequentially after radiation. This will limit potential overlapping adverse effects between hormonal therapy and radiation that may decrease completion of treatment. The sequential approach has not been associated with any harm in clinical outcomes, and there is some suggestion of increased toxicity with concurrent use. However, in patients at high risk of distant recurrence, they felt it would be reasonable to consider concurrent treatment to avoid any delay in therapy. CONCLUSION The consensus of our institution to utilize a sequential approach will standardize the treatment decisions and reduce the risk of failing to initiate hormonal therapy. Despite the lack of level 1 evidence, the Delphi methodology did provide a high level of confidence for our group to choose the sequential approach. The consensus was developed after a review of the literature revealed that there was no clear superiority of one schedule over the other and evidence that concurrent treatment may increase adverse events.
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Affiliation(s)
- Matthew J Cecchini
- Department of Pathology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Edward Yu
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Brian P Yaremko
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA ; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | | | - Kylea Potvin
- Department of Medical Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Tracy Sexton
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - David D'Souza
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA ; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Muriel Brackstone
- Department of Surgical Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Michael Lock
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
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12
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Cecchini MJ, Yu E, Potvin K, D'souza D, Lock M. Concurrent or Sequential Hormonal and Radiation Therapy in Breast Cancer: A Literature Review. Cureus 2015; 7:e364. [PMID: 26623219 PMCID: PMC4659580 DOI: 10.7759/cureus.364] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background and objectives: Adjuvant hormonal therapy is frequently used in the treatment of women with estrogen receptor (ER)/progesterone receptor (PR) positive breast cancer. When radiotherapy is given, hormone therapy may be delivered in a concurrent or sequential manner. Hormonal blockade with tamoxifen or aromatase inhibitors is thought to arrest hormonally dependent cancer cells in the early G1 phase of the cell cycle. This has been theorized to reduce the efficacy of radiation, which is known to be more effective in cells that are actively dividing. Therefore, there has been a reluctance by many to treat with concurrent hormonal and radiation therapy. Methods: We performed a search of the Medline database that led to the identification of 39 studies. Abstract and full-text review of these studies led to the identification of seven English non-review studies in peer-reviewed literature between 1995 and 2015 that addressed the question of timing of radiation and hormonal therapy. Outcome measures were captured from each of the studies. Results: No difference in survival or local-regional recurrence was identified between concurrent versus sequential treatment. Furthermore, no difference in cosmetic outcome or adverse effects was noted for either approach. However, when comparing radiation alone or radiation and hormonal therapy, there was an increased risk of breast and lung fibrosis with combined treatment. Conclusions: Hormone therapy, concurrent or sequential, with radiation results in comparable disease-related outcomes, including survival and recurrence. However, given the theoretical reduction in efficacy and increased rates of fibrosis with concurrent use, it is reasonable to support the use of sequential therapy.
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Affiliation(s)
- Matthew J Cecchini
- Department of Pathology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Edward Yu
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Kylea Potvin
- Department of Medical Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - David D'souza
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
| | - Michael Lock
- Department of Radiation Oncology, London Regional Cancer Program, London, Ontario, CA; Schulich School of Medicine & Dentistry, Western University, London, Ontario, CA
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13
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Cancer du sein : radiothérapie et signalisation œstrogénique. Bull Cancer 2014; 101:714-7. [DOI: 10.1684/bdc.2014.1954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Lara PC, López-Peñalver JJ, Farias VDA, Ruiz-Ruiz MC, Oliver FJ, Ruiz de Almodóvar JM. Direct and bystander radiation effects: a biophysical model and clinical perspectives. Cancer Lett 2013; 356:5-16. [PMID: 24045041 DOI: 10.1016/j.canlet.2013.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/03/2013] [Accepted: 09/08/2013] [Indexed: 12/12/2022]
Abstract
In planning treatment for each new patient, radiation oncologists pay attention to the aspects that they control. Thus their attention is usually focused on volume and dose. The dilemma for the physician is how to protract the treatment in a way that maximizes control of the tumor and minimizes normal tissue injury. The initial radiation-induced damage to DNA may be a biological indicator of the quantity of energy transferred to the DNA. However, until now the biophysical models proposed cannot explain either the early or the late adverse effects of radiation, and a more general theory appears to be required. The bystander component of tumor cell death after radiotherapy measured in many experimental works highlights the importance of confirming these observations in a clinical situation.
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Affiliation(s)
- Pedro Carlos Lara
- Radiation Oncology Department, Hospital Universitario de Gran Canaria Dr Negrín, Barranco de La Ballena s/n, Las Palmas de Gran Canaria, CP 35010, Spain
| | - Jesús Joaquín López-Peñalver
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain
| | - Virgínea de Araújo Farias
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain
| | - M Carmen Ruiz-Ruiz
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain
| | - Francisco Javier Oliver
- Instituto de Parasitología y Biomedicina López Neyra, CSIC, Avda. Conocimiento 4, 18016 Granada, Spain
| | - José Mariano Ruiz de Almodóvar
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain; Hospital Universitario San Cecilio, Avda. Dr. Olóriz s/n, 18012 Granada, Spain.
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15
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Wang J, Yang Q, Haffty BG, Li X, Moran MS. Fulvestrant radiosensitizes human estrogen receptor-positive breast cancer cells. Biochem Biophys Res Commun 2013; 431:146-51. [DOI: 10.1016/j.bbrc.2013.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 01/03/2013] [Indexed: 01/25/2023]
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16
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Hermann RM, Wolff HA, Jarry H, Thelen P, Gruendker C, Rave-Fraenk M, Schmidberger H, Christiansen H. In vitro studies on the modification of low-dose hyper-radiosensitivity in prostate cancer cells by incubation with genistein and estradiol. Radiat Oncol 2008; 3:19. [PMID: 18625043 PMCID: PMC2490684 DOI: 10.1186/1748-717x-3-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 07/14/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND As the majority of prostate cancers (PC) express estrogen receptors, we evaluated the combination of radiation and estrogenic stimulation (estrogen and genistein) on the radiosensitivity of PC cells in vitro. METHODS PC cells LNCaP (androgen-sensitive) and PC-3 (androgen-independent) were evaluated. Estrogen receptor (ER) expression was analyzed by means of immunostaining. Cells were incubated in FCS-free media with genistein 10 microM and estradiol 10 microM 24 h before irradiation and up to 24 h after irradiation. Clonogenic survival, cell cycle changes, and expression of p21 were assessed. RESULTS LNCaP expressed both ER-alpha and ER-beta, PC-3 did not. Incubation of LNCaP and PC-3 with genistein resulted in a significant reduction of clonogenic survival. Incubation with estradiol exhibited in low concentrations (0.01 microM) stimulatory effects, while higher concentrations did not influence survival. Both genistein 10 microM and estradiol 10 microM increased low-dose hyper-radiosensitivity [HRS] in LNCaP, while hormonal incubation abolished HRS in PC-3. In LNCaP cells hormonal stimulation inhibited p21 induction after irradiation with 4 Gy. In PC-3 cells, the proportion of cells in G2/M was increased after irradiation with 4 Gy. CONCLUSION We found an increased HRS to low irradiation doses after incubation with estradiol or genistein in ER-alpha and ER-beta positive LNCaP cells. This is of high clinical interest, as this tumor model reflects a locally advanced, androgen dependent PC. In contrast, in ER-alpha and ER-beta negative PC-3 cells we observed an abolishing of the HRS to low irradiation doses by hormonal stimulation. The effects of both tested compounds on survival were ER and p53 independent. Since genistein and estradiol effects in both cell lines were comparable, neither ER- nor p53-expression seemed to play a role in the linked signalling. Nevertheless both compounds targeted the same molecular switch. To identify the underlying molecular mechanisms, further studies are needed.
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Affiliation(s)
- Robert Michael Hermann
- Department of Radiotherapy and Radiooncology, University hospital Goettingen, Robert-Koch-Str, 40, 37075, Goettingen, Germany.
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17
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Shao C, Folkard M, Held KD, Prise KM. Estrogen enhanced cell-cell signalling in breast cancer cells exposed to targeted irradiation. BMC Cancer 2008; 8:184. [PMID: 18590532 PMCID: PMC2443807 DOI: 10.1186/1471-2407-8-184] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Accepted: 06/30/2008] [Indexed: 12/11/2022] Open
Abstract
Background Radiation-induced bystander responses, where cells respond to their neighbours being irradiated are being extensively studied. Although evidence shows that bystander responses can be induced in many types of cells, it is not known whether there is a radiation-induced bystander effect in breast cancer cells, where the radiosensitivity may be dependent on the role of the cellular estrogen receptor (ER). This study investigated radiation-induced bystander responses in estrogen receptor-positive MCF-7 and estrogen receptor-negative MDA-MB-231 breast cancer cells. Methods The influence of estrogen and anti-estrogen treatments on the bystander response was determined by individually irradiating a fraction of cells within the population with a precise number of helium-3 using a charged particle microbeam. Damage was scored as chromosomal damage measured as micronucleus formation. Results A bystander response measured as increased yield of micronucleated cells was triggered in both MCF-7 and MDA-MB-231 cells. The contribution of the bystander response to total cell damage in MCF-7 cells was higher than that in MDA-MB-231 cells although the radiosensitivity of MDA-MB-231 was higher than MCF-7. Treatment of cells with 17β-estradiol (E2) increased the radiosensitivity and the bystander response in MCF-7 cells, and the effect was diminished by anti-estrogen tamoxifen (TAM). E2 also increased the level of intracellular reactive oxygen species (ROS) in MCF-7 cells in the absence of radiation. In contrast, E2 and TAM had no influence on the bystander response and ROS levels in MDA-MB-231 cells. Moreover, the treatment of MCF-7 cells with antioxidants eliminated both the E2-induced ROS increase and E2-enhanced bystander response triggered by the microbeam irradiation, which indicates that ROS are involved in the E2-enhanced bystander micronuclei formation after microbeam irradiation. Conclusion The observation of bystander responses in breast tumour cells may offer new potential targets for radiation-based therapies in the treatment of breast cancer.
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Affiliation(s)
- Chunlin Shao
- Institute of Radiation Medicine, Fudan University, No.2094 Xie-Tu Road, Shanghai 200032, PR China.
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18
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Schmidberger H, Hermann RM, Hess CF, Emons G. Combination of anti-estrogenic therapy with radiation in breast cancer: simultaneous or sequential treatment? Oncol Res Treat 2005; 28:275-80. [PMID: 15867485 DOI: 10.1159/000085153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adjuvant radiotherapy and adjuvant endocrine therapy are commonly given to patients with invasive breast cancer or with ductal carcinoma in situ (DCIS). Although both therapies have been well established through a number of randomized studies, little is known about a possible interaction of both treatment modalities if they are given simultaneously. A number of in vitro studies indicated that tamoxifen treatment might reduce the intrinsic radiosensitivity of MCF-7 breast cancer cells. Conversely, estradiol treatment increased the intrinsic radiosensitivity of MCF-7 cells. This phenomenon has not been found in clinical studies. Retrospective analyses of prospectively randomized clinical studies did not indicate an antagonistic effect of tamoxifen on the effectiveness of ionizing radiation (XRT), since local control has been consistently higher when XRT was combined with tamoxifen, compared to treatment with XRT alone, regardless of whether tamoxifen was started simultaneously with radiotherapy or after completion of radiotherapy. Currently there are no clinical data available that would suggest an adverse effect of adjuvant tamoxifen treatment started prior to or simultaneously with radiotherapy in breast cancer or DCIS. However, since an antagonistic effect of tamoxifen and simultaneous chemotherapy has been reported recently, the issue of simultaneous.
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MESH Headings
- Breast Neoplasms/drug therapy
- Breast Neoplasms/mortality
- Breast Neoplasms/radiotherapy
- Carcinoma, Ductal, Breast/drug therapy
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/radiotherapy
- Carcinoma, Intraductal, Noninfiltrating/drug therapy
- Carcinoma, Intraductal, Noninfiltrating/mortality
- Carcinoma, Intraductal, Noninfiltrating/radiotherapy
- Cell Survival/drug effects
- Cell Survival/radiation effects
- Combined Modality Therapy
- Drug Administration Schedule
- Estrogen Antagonists/administration & dosage
- Estrogen Antagonists/adverse effects
- Female
- Humans
- Outcome and Process Assessment, Health Care
- Radiation Tolerance/drug effects
- Radiotherapy Dosage
- Randomized Controlled Trials as Topic
- Retrospective Studies
- Tamoxifen/administration & dosage
- Tamoxifen/adverse effects
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/radiation effects
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Herskind C, Steil V, Kraus-Tiefenbacher U, Wenz F. Radiobiological aspects of intraoperative radiotherapy (IORT) with isotropic low-energy X rays for early-stage breast cancer. Radiat Res 2005; 163:208-15. [PMID: 15658897 DOI: 10.1667/rr3292] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to model the distribution of biological effect around a miniature isotropic X-ray source incorporating spherical applicators for single-dose or hypo-fractionated partial-breast intraoperative radiotherapy. A modification of the linear-quadratic formalism was used to calculate the relative biological effectiveness (RBE) of 50 kV X rays as a function of dose and irradiation time for late-reacting normal tissue and tumor cells. The response was modeled as a function of distance in the tissue based on the distribution of equivalent dose and published dose-response data for pneumonitis and subcutaneous fibrosis after single-dose conventional irradiation. Furthermore, the spatial distribution of tumor cell inactivation was assessed. The RBE for late reactions approached unity at the applicator surface but increased as the absorbed dose decreased with increasing distance from the applicator surface. The ED50 for pneumonitis was estimated to be reached at a depth of 6-11 mm in the tissue and that for subcutaneous fibrosis at 3-6 mm, depending on the applicator diameter and whether the effect of recovery was included. Thus lung tissue would be spared because of the thickness of the thorax wall. The RBE for tumor cells was higher than for late-reacting tissue. The applicator diameter is an important parameter in determining the range of tumor cell control in the irradiated tumor bed.
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Affiliation(s)
- Carsten Herskind
- Department of Radiation Oncology, Inst. of Clinical Radiology, Mannheim Medical Center, University of Heidelberg, Germany.
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20
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Davis J, Pither RJ. Biochemical responses in cultured cells following exposure to (89)SrCl(2): potential relevance to the mechanism of action in pain palliation. Eur J Cancer 2001; 37:2464-9. [PMID: 11720844 DOI: 10.1016/s0959-8049(01)00305-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
(89)SrCl(2) is currently used as a systemic radioactive palliative treatment for painful osseous metastases associated with an osteoblastic reaction in bone. However, the biological mechanism by which (89)SrCl(2) mediates pain palliation remains unclear. In this study, attempts were made to elucidate the mechanisms by which (89)SrCl(2) might influence pain at these sites. Both the direct radiotoxic effects of (89)SrCl(2) on cell viability and its influence on cellular biosynthetic activity were investigated. The direct radiotoxic effects of (89)SrCl(2) and X-rays were compared using the prostate carcinoma cell line, PC-3. Comparable effects upon PC-3 cell viability were seen in response to exposure to an equivalent dose given by (89)SrCl(2) and X-rays (2 Gy). Experiments to investigate the indirect action of (89)SrCl(2) exposure employed the MC3T3-E1 cell line and focused on their production of Prostaglandin E(2) (PGE(2)) and interleukin-6 (IL-6). Exposure of the MC3T3-E1 cell line to (89)SrCl(2) resulted in an increased production of PGE(2) in a concentration-dependent manner. No increased PGE(2) production was seen by the MC3T3-E1 cells in response to X-ray exposure either in the presence or absence of SrCl(2). IL-6 was produced by the MC3T3-E1 cells in response to (89)SrCl(2) exposure via a PGE(2)-mediated pathway. This study demonstrates the release of potent biochemical modifiers of bone turnover in response to the systemically applied radiotherapeutic (89)SrCl(2). This strongly suggests the mechanism of pain palliation by (89)SrCl(2) is likely to result from a complex interaction of direct and indirect radiation-induced effects.
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Affiliation(s)
- J Davis
- Amersham plc, Imaging Research and Development, Amersham Laboratories, White Lion Road, Amersham, Bucks HP7 9LL, UK
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21
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Stevens RG, Morris JE, Anderson LE. Hemochromatosis Heterozygotes May Constitute a Radiation-Sensitive Subpopulation. Radiat Res 2000. [DOI: 10.1667/0033-7587(2000)153[0844:hhmcar]2.0.co;2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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22
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Núñez MI, Guerrero MR, López E, del Moral MR, Valenzuela MT, Siles E, Villalobos M, Pedraza V, Peacock JH, Ruiz de Almodóvar JM. DNA damage and prediction of radiation response in lymphocytes and epidermal skin human cells. Int J Cancer 1998; 76:354-61. [PMID: 9579572 DOI: 10.1002/(sici)1097-0215(19980504)76:3<354::aid-ijc12>3.0.co;2-b] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The success of radiotherapy in eradicating tumours depends on the total radiation dose, but what limits this dose is the tolerance of the normal tissues within the treatment volume. Studies involving fibroblast survival have demonstrated the theoretical feasibility of a predictive assay of radiation sensitivity, but such an assay is still far from clinical application. Using pulsed-field gel electrophoresis (PFGE), we have quantified the initial "apparent" number of DNA double-strand breaks (dsb) induced by the radiation as an alternative measure of sensitivity in 2 different normal cell types from the same patients, epidermal skin cells and lymphocytes. We found significant inter-individual variation in the measured dsb (1-5 dsb/Gy/DNA unit). We also found a linear correlation between molecular damage in lymphocytes and skin samples from the same patient (slope = 0.83; r = 0.694; p = 0.0001). These results suggest that the initial number of dsb could be used as an indicator of the in vivo response to radiation.
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Affiliation(s)
- M I Núñez
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Granada, Spain
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