Francesco Petragnano1, Ilaria Pietrantoni1, Valentina Di Nisio2, Irene Fasciani1, Andrea Del Fattore3, Carlo Capalbo4, Sara Cheleschi5, Paolo Tini6,7, Simone Orelli8, Silvia Codenotti9, Maria Antonietta Mazzei10, Giuseppe D'Ermo11, Gaetano Pannitteri12, Mario Tombolini13, Paola De Cesaris14, Anna Riccioli14, Antonio Filippini14, Luisa Milazzo15, Francesca Vulcano15, Alessandro Fanzani9, Roberto Maggio1, Francesco Marampon8, Vincenzo Tombolini8. 1. Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy. 2. Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy. 3. Bone Physiopathology Unit Genetics and Rare Diseases Research Area, Bambino Gesù Children's Hospital, Rome, Italy. 4. Department of Molecular Medicine, "Sapienza" University of Rome, Rome, Italy. 5. Department of Medicine, Surgery and Neuroscience, Rheumatology Unit, University of Siena, Policlinico Le Scotte, Siena, Italy. 6. Department of Biology, College of Science and Technology, Temple University, Philadelphia, PA, USA. 7. Unit of Radiation Oncology, University Hospital of Siena, Siena, Italy. 8. Department of Radiology, Radiotherapy, Oncology, Anatomopathology, "Sapienza" University of Rome, Rome, Italy. 9. Department of Molecular and Translational Medicine, Division of Biotechnology, University of Brescia, Brescia, Italy. 10. Unit of Medical Imaging, University Hospital of Siena, Siena, Italy. 11. Department of Surgery "Pietro Valdoni", "Sapienza" University of Rome, Rome, Italy. 12. Department of Cardiovascular, Respiratory, Nephrologic, Anaesthesiologic and Geriatric Sciences, Sapienza University, Rome, Italy. 13. Department of Sense Organs, "Sapienza" University of Rome, Rome, Italy. 14. Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Section of Histology and Medical Embryology, "Sapienza" University, Rome, Italy. 15. Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.
Abstract
Purpose: Radiation therapy (RT), by using ionizing radiation (IR), destroys cancer cells inducing DNA damage. Despite several studies are continuously performed to identify the best curative dose of IR, the role of dose-rate, IR delivered per unit of time, on tumor control is still largely unknown.Materials and methods: Rhabdomyosarcoma (RMS) and prostate cancer (PCa) cell lines were irradiated with 2 or 10 Gy delivered at dose-rates of 1.5, 2.5, 5.5 and 10.1 Gy/min. Cell-survival rate and cell cycle distribution were evaluated by clonogenic assays and flow cytometry, respectively. The production of reactive oxygen species (ROS) was detected by cytometry. Quantitative polymerase chain reaction assessed the expression of anti-oxidant-related factors including NRF2, SODs, CAT and GPx4 and miRNAs (miR-22, -126, -210, -375, -146a, -34a). Annexin V and caspase-8, -9 and -3 activity were assessed to characterize cell death. Senescence was determined by assessing β-galactosidase (SA-β-gal) activity. Immunoblotting was performed to assess the expression/activation of: i) phosphorylated H2AX (γ-H2AX), markers of DNA double strand breaks (DSBs); ii) p19Kip1/Cip1, p21Waf1/Cip1 and p27Kip1/Cip1, senescence-related-markers; iii) p62, LC3-I and LC3-II, regulators of autophagy; iv) ATM, RAD51, DNA-PKcs, Ku70 and Ku80, mediators of DSBs repair. Results: Low dose-rate (LDR) more efficiently induced apoptosis and senescence in RMS while high dose-rate (HDR) necrosis in PCa. This paralleled with a lower ability of LDR-RMS and HDR-PCa irradiated cells to activate DSBs repair. Modulating the dose rate did not differently affect the anti-oxidant ability of cancer cells. Conclusion: The present results indicate that a stronger cytotoxic effect was induced by modulating the dose-rate in a cancer cell-dependent manner, this suggesting that choose the dose-rate based on the individual patient's tumor characteristics could be strategic for effective RT exposures.
Purpose: Radiation therapy (RT), by using ionizing radiation (IR), destroys cancer cells inducing DNA damage. Despite several studies are continuously performed to identify the best curative dose of IR, the role of dose-rate, IR delivered per unit of time, on tumor control is still largely unknown.Materials and methods: Rhabdomyosarcoma (RMS) and prostate cancer (PCa) cell lines were irradiated with 2 or 10 Gy delivered at dose-rates of 1.5, 2.5, 5.5 and 10.1 Gy/min. Cell-survival rate and cell cycle distribution were evaluated by clonogenic assays and flow cytometry, respectively. The production of reactive oxygen species (ROS) was detected by cytometry. Quantitative polymerase chain reaction assessed the expression of anti-oxidant-related factors including NRF2, SODs, CAT and GPx4 and miRNAs (miR-22, -126, -210, -375, -146a, -34a). Annexin V and caspase-8, -9 and -3 activity were assessed to characterize cell death. Senescence was determined by assessing β-galactosidase (SA-β-gal) activity. Immunoblotting was performed to assess the expression/activation of: i) phosphorylated H2AX (γ-H2AX), markers of DNA double strand breaks (DSBs); ii) p19Kip1/Cip1, p21Waf1/Cip1 and p27Kip1/Cip1, senescence-related-markers; iii) p62, LC3-I and LC3-II, regulators of autophagy; iv) ATM, RAD51, DNA-PKcs, Ku70 and Ku80, mediators of DSBs repair. Results: Low dose-rate (LDR) more efficiently induced apoptosis and senescence in RMS while high dose-rate (HDR) necrosis in PCa. This paralleled with a lower ability of LDR-RMS and HDR-PCa irradiated cells to activate DSBs repair. Modulating the dose rate did not differently affect the anti-oxidant ability of cancer cells. Conclusion: The present results indicate that a stronger cytotoxic effect was induced by modulating the dose-rate in a cancer cell-dependent manner, this suggesting that choose the dose-rate based on the individual patient's tumor characteristics could be strategic for effective RT exposures.
Entities:
Keywords:
Rhabdomyosarcoma; dose rate; double-strand DNA breaks; prostate cancer; radiotherapy; reactive oxygen species
Authors: Igor Piotrowski; Katarzyna Kulcenty; Wiktoria Suchorska; Marcin Rucinski; Karol Jopek; Marta Kruszyna-Mochalska; Agnieszka Skrobala; Piotr Romanski; Adam Ryczkowski; Dorota Borowicz; Natalia Matuszak; Julian Malicki Journal: Cancers (Basel) Date: 2022-05-30 Impact factor: 6.575