1
|
Cogno N, Bauer R, Durante M. An Agent-Based Model of Radiation-Induced Lung Fibrosis. Int J Mol Sci 2022; 23:13920. [PMID: 36430398 PMCID: PMC9693125 DOI: 10.3390/ijms232213920] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/03/2022] [Accepted: 11/05/2022] [Indexed: 11/16/2022] Open
Abstract
Early- and late-phase radiation-induced lung injuries, namely pneumonitis and lung fibrosis (RILF), severely constrain the maximum dose and irradiated volume in thoracic radiotherapy. As the most radiosensitive targets, epithelial cells respond to radiation either by undergoing apoptosis or switching to a senescent phenotype that triggers the immune system and damages surrounding healthy cells. Unresolved inflammation stimulates mesenchymal cells' proliferation and extracellular matrix (ECM) secretion, which irreversibly stiffens the alveolar walls and leads to respiratory failure. Although a thorough understanding is lacking, RILF and idiopathic pulmonary fibrosis share multiple pathways and would mutually benefit from further insights into disease progression. Furthermore, current normal tissue complication probability (NTCP) models rely on clinical experience to set tolerance doses for organs at risk and leave aside mechanistic interpretations of the undergoing processes. To these aims, we implemented a 3D agent-based model (ABM) of an alveolar duct that simulates cell dynamics and substance diffusion following radiation injury. Emphasis was placed on cell repopulation, senescent clearance, and intra/inter-alveolar bystander senescence while tracking ECM deposition. Our ABM successfully replicates early and late fibrotic response patterns reported in the literature along with the ECM sigmoidal dose-response curve. Moreover, surrogate measures of RILF severity via a custom indicator show qualitative agreement with published fibrosis indices. Finally, our ABM provides a fully mechanistic alveolar survival curve highlighting the need to include bystander damage in lung NTCP models.
Collapse
Affiliation(s)
- Nicolò Cogno
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - Roman Bauer
- Department of Computer Science, University of Surrey, Guildford GU2 7XH, UK
| | - Marco Durante
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| |
Collapse
|
2
|
Madas BG, Boei J, Fenske N, Hofmann W, Mezquita L. Effects of spatial variation in dose delivery: what can we learn from radon-related lung cancer studies? RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:561-577. [PMID: 36208308 PMCID: PMC9630403 DOI: 10.1007/s00411-022-00998-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 09/28/2022] [Indexed: 05/14/2023]
Abstract
Exposure to radon progeny results in heterogeneous dose distributions in many different spatial scales. The aim of this review is to provide an overview on the state of the art in epidemiology, clinical observations, cell biology, dosimetry, and modelling related to radon exposure and its association with lung cancer, along with priorities for future research. Particular attention is paid on the effects of spatial variation in dose delivery within the organs, a factor not considered in radiation protection. It is concluded that a multidisciplinary approach is required to improve risk assessment and mechanistic understanding of carcinogenesis related to radon exposure. To achieve these goals, important steps would be to clarify whether radon can cause other diseases than lung cancer, and to investigate radon-related health risks in children or persons at young ages. Also, a better understanding of the combined effects of radon and smoking is needed, which can be achieved by integrating epidemiological, clinical, pathological, and molecular oncology data to obtain a radon-associated signature. While in vitro models derived from primary human bronchial epithelial cells can help to identify new and corroborate existing biomarkers, they also allow to study the effects of heterogeneous dose distributions including the effects of locally high doses. These novel approaches can provide valuable input and validation data for mathematical models for risk assessment. These models can be applied to quantitatively translate the knowledge obtained from radon exposure to other exposures resulting in heterogeneous dose distributions within an organ to support radiation protection in general.
Collapse
Affiliation(s)
- Balázs G Madas
- Environmental Physics Department, Centre for Energy Research, Budapest, Hungary.
| | - Jan Boei
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Nora Fenske
- Federal Office for Radiation Protection, Munich (Neuherberg), Germany
| | - Werner Hofmann
- Biological Physics, Department of Chemistry and Physics of Materials, University of Salzburg, Salzburg, Austria
| | - Laura Mezquita
- Medical Oncology Department, Hospital Clinic of Barcelona, Barcelona, Spain
- Laboratory of Translational Genomic and Targeted Therapies in Solid Tumors, IDIBAPS, Barcelona, Spain
| |
Collapse
|
3
|
Abu Shqair A, Kim EH. Multi-scaled Monte Carlo calculation for radon-induced cellular damage in the bronchial airway epithelium. Sci Rep 2021; 11:10230. [PMID: 33986410 PMCID: PMC8119983 DOI: 10.1038/s41598-021-89689-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/21/2021] [Indexed: 12/19/2022] Open
Abstract
Radon is a leading cause of lung cancer in indoor public and mining workers. Inhaled radon progeny releases alpha particles, which can damage cells in the airway epithelium. The extent and complexity of cellular damage vary depending on the alpha particle's kinetic energy and cell characteristics. We developed a framework to quantitate the cellular damage on the nanometer and micrometer scales at different intensities of exposure to radon progenies Po-218 and Po-214. Energy depositions along the tracks of alpha particles that were slowing down were simulated on a nanometer scale using the Monte Carlo code Geant4-DNA. The nano-scaled track histories in a 5 μm radius and 1 μm-thick cylindrical volume were integrated into the tracking scheme of alpha trajectories in a micron-scale bronchial epithelium segment in the user-written SNU-CDS program. Damage distribution in cellular DNA was estimated for six cell types in the epithelium. Deep-sited cell nuclei in the epithelium would have less chance of being hit, but DNA damage from a single hit would be more serious, because low-energy alpha particles of high LET would hit the nuclei. The greater damage in deep-sited nuclei was due to the 7.69 MeV alpha particles emitted from Po-214. From daily work under 1 WL of radon concentration, basal cells would respond with the highest portion of complex DSBs among the suspected progenitor cells in the most exposed regions of the lung epithelium.
Collapse
Affiliation(s)
- Ali Abu Shqair
- Department of Nuclear Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eun-Hee Kim
- Department of Nuclear Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
| |
Collapse
|
4
|
Hofmann W, Li WB, Friedland W, Miller BW, Madas B, Bardiès M, Balásházy I. Internal microdosimetry of alpha-emitting radionuclides. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:29-62. [PMID: 31863162 PMCID: PMC7012986 DOI: 10.1007/s00411-019-00826-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 12/08/2019] [Indexed: 05/27/2023]
Abstract
At the tissue level, energy deposition in cells is determined by the microdistribution of alpha-emitting radionuclides in relation to sensitive target cells. Furthermore, the highly localized energy deposition of alpha particle tracks and the limited range of alpha particles in tissue produce a highly inhomogeneous energy deposition in traversed cell nuclei. Thus, energy deposition in cell nuclei in a given tissue is characterized by the probability of alpha particle hits and, in the case of a hit, by the energy deposited there. In classical microdosimetry, the randomness of energy deposition in cellular sites is described by a stochastic quantity, the specific energy, which approximates the macroscopic dose for a sufficiently large number of energy deposition events. Typical examples of the alpha-emitting radionuclides in internal microdosimetry are radon progeny and plutonium in the lungs, plutonium and americium in bones, and radium in targeted radionuclide therapy. Several microdosimetric approaches have been proposed to relate specific energy distributions to radiobiological effects, such as hit-related concepts, LET and track length-based models, effect-specific interpretations of specific energy distributions, such as the dual radiation action theory or the hit-size effectiveness function, and finally track structure models. Since microdosimetry characterizes only the initial step of energy deposition, microdosimetric concepts are most successful in exposure situations where biological effects are dominated by energy deposition, but not by subsequently operating biological mechanisms. Indeed, the simulation of the combined action of physical and biological factors may eventually require the application of track structure models at the nanometer scale.
Collapse
Affiliation(s)
- Werner Hofmann
- Biological Physics, Department of Chemistry and Physics of Materials, University of Salzburg, Hellbrunner Str. 34, 5020, Salzburg, Austria.
| | - Wei Bo Li
- Institute of Radiation Medicine, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
| | - Werner Friedland
- Institute of Radiation Medicine, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Brian W Miller
- Department of Radiation Oncology, School of Medicine, University of Colorado, Aurora, CO, 80045, USA
- College of Optical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Balázs Madas
- Environmental Physics Department, MTA Centre for Energy Research, Budapest, Hungary
| | - Manuel Bardiès
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, INSERM Université Paul Sabatier, Toulouse, France
| | - Imre Balásházy
- Environmental Physics Department, MTA Centre for Energy Research, Budapest, Hungary
| |
Collapse
|
5
|
Drozsdik EJ, Madas BG. QUANTITATIVE ANALYSIS OF THE POTENTIAL ROLE OF BASAL CELL HYPERPLASIA IN THE RELATIONSHIP BETWEEN CLONAL EXPANSION AND RADON CONCENTRATION. RADIATION PROTECTION DOSIMETRY 2019; 183:237-241. [PMID: 30668805 DOI: 10.1093/rpd/ncy302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 12/24/2018] [Indexed: 05/27/2023]
Abstract
Applying the two-stage clonal expansion model to epidemiology of lung cancer among uranium miners, it has been revealed that radon acts as a promoting agent facilitating the clonal expansion of already mutated cells. Clonal expansion rate increases non-linearly by radon concentration showing a plateau above a given exposure rate. The underlying mechanisms remain unclear. Earlier we proposed that progenitor cell hyperplasia may be induced upon chronic radon exposure. The objective of the present study is to test whether the induction of hyperplasia may provide a quantitative explanation for the plateau in clonal expansion rate. For this purpose, computational epithelium models were prepared with different number of basal cells. Cell nucleus hits were computed by an own-developed Monte-Carlo code. Surviving fractions were estimated based on the number of cell nucleus hits. Cell division rate was computed supposing equilibrium between cell death and cell division. It was also supposed that clonal expansion rate is proportional to cell division rate, and therefore the relative increase in cell division rate and clonal expansion rate are the same functions of exposure rate. While the simulation results highly depend on model parameters with high uncertainty, a parameter set has been found resulting in a cell division rate-exposure rate relationship corresponding to the plateau in clonal expansion rate. Due to the high uncertainty of the applied parameters, however, further studies are required to decide whether the induction of hyperplasia is responsible for the non-linear increase in clonal expansion rate or not. Nevertheless, the present study exemplifies how computational modelling can contribute to the integration of observational and experimental radiation protection research.
Collapse
Affiliation(s)
- Emese J Drozsdik
- Department of Biological Physics, Doctoral School of Physics, ELTE Eötvös Loránd University, Budapest, Hungary
- Radiation Biophysics Group, Environmental Physics Department, MTA Centre for Energy Research, Budapest, Hungary
| | - Balázs G Madas
- Radiation Biophysics Group, Environmental Physics Department, MTA Centre for Energy Research, Budapest, Hungary
| |
Collapse
|
6
|
Madas B, Drozsdik E. Radon induced hyperplasia may provide an explanation for inverse exposure rate effect. BIO WEB OF CONFERENCES 2019. [DOI: 10.1051/bioconf/20191405005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|