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Devic C, Ferlazzo ML, Berthel E, Foray N. Influence of Individual Radiosensitivity on the Hormesis Phenomenon: Toward a Mechanistic Explanation Based on the Nucleoshuttling of ATM Protein. Dose Response 2020; 18:1559325820913784. [PMID: 32425719 PMCID: PMC7218313 DOI: 10.1177/1559325820913784] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/02/2020] [Accepted: 02/18/2020] [Indexed: 12/16/2022] Open
Abstract
Hormesis is a low-dose phenomenon that has been reported to occur, to different extents, in animals, plants, and microorganisms. However, a review of the literature shows that only a few reports describe it in humans. Also, the diversity of experimental protocols and cellular models used makes deciphering the mechanisms of hormesis difficult. In humans, hormesis mostly appears in the 20 to 75 mGy dose range and in nontransformed, radioresistant cells. In a previous paper by Devic et al, a biological interpretation of the adaptive response (AR) phenomenon was proposed using our model that is based on the radiation-induced nucleoshuttling of the ATM protein (the RIANS model). Here, we showed that the 20 to 75 mGy dose range corresponds to a maximum amount of ATM monomers diffusing into the nucleus, while no DNA double-strand breaks is produced by radiation. These ATM monomers are suggested to help in recognizing and repairing spontaneous DNA breaks accumulated in cells and contribute to reductions in genomic instability and aging. The RIANS model also permitted the biological interpretation of hypersensitivity to low doses (HRS)-another low-dose phenomenon. Hence, for the first time to our knowledge, hormesis, AR, and HRS can be explained using the same unified molecular model.
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Affiliation(s)
- Clément Devic
- Institut National de la Santé et de la Recherche Médicale (INSERM), UA8 Unit "Radiations: Defense, Health and Environment," Centre Léon-Bérard, Lyon, France.,Fibermetrix Company, Strasbourg, France
| | - Mélanie L Ferlazzo
- Institut National de la Santé et de la Recherche Médicale (INSERM), UA8 Unit "Radiations: Defense, Health and Environment," Centre Léon-Bérard, Lyon, France
| | - Elise Berthel
- Institut National de la Santé et de la Recherche Médicale (INSERM), UA8 Unit "Radiations: Defense, Health and Environment," Centre Léon-Bérard, Lyon, France
| | - Nicolas Foray
- Institut National de la Santé et de la Recherche Médicale (INSERM), UA8 Unit "Radiations: Defense, Health and Environment," Centre Léon-Bérard, Lyon, France
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Merrill RM, Frutos AM. Ecological Evidence for Lower Risk of Lymphoma with Greater Exposure to Sunlight and Higher Altitude. High Alt Med Biol 2020; 21:37-44. [DOI: 10.1089/ham.2019.0054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Ray M. Merrill
- Department of Public Health, College of Life Sciences, Brigham Young University, Provo, Utah
| | - Aaron M. Frutos
- Department of Public Health, College of Life Sciences, Brigham Young University, Provo, Utah
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Vaiserman A, Koliada A, Zabuga O, Socol Y. Health Impacts of Low-Dose Ionizing Radiation: Current Scientific Debates and Regulatory Issues. Dose Response 2018; 16:1559325818796331. [PMID: 30263019 PMCID: PMC6149023 DOI: 10.1177/1559325818796331] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 12/31/2022] Open
Abstract
Health impacts of low-dose ionizing radiation are significant in important fields such as X-ray imaging, radiation therapy, nuclear power, and others. However, all existing and potential applications are currently challenged by public concerns and regulatory restrictions. We aimed to assess the validity of the linear no-threshold (LNT) model of radiation damage, which is the basis of current regulation, and to assess the justification for this regulation. We have conducted an extensive search in PubMed. Special attention has been given to papers cited in comprehensive reviews of the United States (2006) and French (2005) Academies of Sciences and in the United Nations Scientific Committee on Atomic Radiation 2016 report. Epidemiological data provide essentially no evidence for detrimental health effects below 100 mSv, and several studies suggest beneficial (hormetic) effects. Equally significant, many studies with in vitro and in animal models demonstrate that several mechanisms initiated by low-dose radiation have beneficial effects. Overall, although probably not yet proven to be untrue, LNT has certainly not been proven to be true. At this point, taking into account the high price tag (in both economic and human terms) borne by the LNT-inspired regulation, there is little doubt that the present regulatory burden should be reduced.
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Merrill RM, Frutos A. Reduced Lung Cancer Mortality With Lower Atmospheric Pressure. Dose Response 2018; 16:1559325818769484. [PMID: 29706845 PMCID: PMC5912279 DOI: 10.1177/1559325818769484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/07/2018] [Accepted: 02/13/2018] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Research has shown that higher altitude is associated with lower risk of lung cancer and improved survival among patients. The current study assessed the influence of county-level atmospheric pressure (a measure reflecting both altitude and temperature) on age-adjusted lung cancer mortality rates in the contiguous United States, with 2 forms of spatial regression. METHODS Ordinary least squares regression and geographically weighted regression models were used to evaluate the impact of climate and other selected variables on lung cancer mortality, based on 2974 counties. RESULTS Atmospheric pressure was significantly positively associated with lung cancer mortality, after controlling for sunlight, precipitation, PM2.5 (µg/m3), current smoker, and other selected variables. Positive county-level β coefficient estimates (P < .05) for atmospheric pressure were observed throughout the United States, higher in the eastern half of the country. CONCLUSION The spatial regression models showed that atmospheric pressure is positively associated with age-adjusted lung cancer mortality rates, after controlling for other selected variables.
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Affiliation(s)
- Ray M. Merrill
- Department of Health Science, College of Life Sciences, Brigham Young University, Provo, UT, USA
| | - Aaron Frutos
- Department of Health Science, College of Life Sciences, Brigham Young University, Provo, UT, USA
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Abstract
Thiersch, Markus, and Erik R. Swenson. High altitude and cancer mortality. High Alt Med Biol 19:116-123, 2018.-Humans living at high altitude (HA) are exposed to chronic (hypobaric) hypoxia. Despite the permanent stress of hypoxic exposure, humans populating HA areas have reduced cancer mortality over a broad spectrum of cancer types. In fact, the majority of the physiological adaptive processes at HA occurring in response to hypoxia might be the driving force for reduced cancer mortality at HA. In this review, we summarize epidemiological and animal studies that compare cancer incidence and cancer mortality between HA and low altitude or between hypoxia and normoxia, respectively. We discuss the potential role of oxygen-independent and oxygen-dependent mechanisms that might contribute to reduced cancer mortality at HA. Reactive oxygen species and their detoxification as well as the hypoxia-inducible factors are especially promising targets and may be related to why cancer mortality is reduced at HA. In addition, we briefly discuss two aspects with a proven impact on tumorigenesis, namely the immune system and tumor surveillance as well as HA-induced metabolic changes. Further animal and clinical studies are clearly needed to explain why cancer mortality is reduced at HA and to decide whether HA or hypoxia-based therapeutic approaches could be implemented for cancer treatment. However, exposure to HA activates multiple adaptive mechanisms (oxygen independent and oxygen dependent) sharing common pathways as well as activating counteracting pathways, which complicate the identification of specific HA-induced mechanisms of tumor suppression.
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Affiliation(s)
- Markus Thiersch
- 1 Vetsuisse Faculty, Institute of Veterinary Physiology, University of Zurich , Zurich, Switzerland .,2 Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich , Zurich, Switzerland
| | - Erik R Swenson
- 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Washington , Seattle, Washington.,4 Medical Service, Veterans Affairs Puget Sound Health Care System , Seattle, Washington
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Reduced cancer mortality at high altitude: The role of glucose, lipids, iron and physical activity. Exp Cell Res 2017; 356:209-216. [PMID: 28344053 DOI: 10.1016/j.yexcr.2017.03.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 03/22/2017] [Indexed: 12/21/2022]
Abstract
Residency at high altitude (HA) demands adaptation to challenging environmental conditions with hypobaric hypoxia being the most important one. Epidemiological and experimental data suggest that chronic exposure to HA reduces cancer mortality and lowers prevalence of metabolic disorders like diabetes and obesity implying that adaption to HA modifies a broad spectrum of physiological, metabolic and cellular programs with a generally beneficial outcome for humans. However, the complexity of multiple, potentially tumor-suppressive pathways at HA impedes the understanding of mechanisms leading to reduced cancer mortality. Many adaptive processes at HA are tightly interconnected and thus it cannot be ruled out that the entirety or at least some of the HA-related alterations act in concert to reduce cancer mortality. In this review we discuss tumor formation as a concept of competition between healthy and cancer cells with improved fitness - and therefore higher competitiveness - of healthy cells at high altitude. We discuss HA-related changes in glucose, lipid and iron metabolism that may have an impact on tumorigenesis. Additionally, we discuss two parameters with a strong impact on tumorigenesis, namely drug metabolism and physical activity, to underpin their potential contribution to HA-dependent reduced cancer mortality. Future studies are needed to unravel why cancer mortality is reduced at HA and how this knowledge might be used to prevent and to treat cancer patients.
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Jena PK, Bandyopadhyay C, Mathur MR, Das S. Extending application of the 'hardcore' definition to smokeless tobacco use: estimates from a nationally representative population in India and its implications. Asian Pac J Cancer Prev 2016; 13:5959-63. [PMID: 23464385 DOI: 10.7314/apjcp.2012.13.12.5959] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The term 'hardcore' has been applied to use of smoking tobacco and generally referred to as the inability or unwillingness of regular smokers to quit. The component constructs of hardcore except nicotine dependence are product neutral. With the use of 'time to first chew' as a measure of nicotine dependence, hardcore definition can be extended to characterize smokeless tobacco users. Hardcore users respond less to tobacco cessation interventions, and are prone to tobacco induced diseases including cancer. Thus identifying hardcore users would help in estimate the burden of high risk population for tobacco induced diseases. Smokeless tobacco use is predominant and accounts for more than 50% of oral cancer in India. Hence, hardcore chewing information could be used for planning of tobacco and cancer control interventions. The objective of this study was to assess the prevalence and associated factors of hardcore smokeless tobacco use in India. MATERIALS AND METHODS Global Adult Tobacco Survey (GATS)-India 2010 data were analyzed to quantify hardcore smokeless tobacco use in India with following five criteria: (1) current daily smokeless tobacco use; (2) no quit attempt in the past 12 months of survey or last quit attempt of less than 24 hours duration; (3) no intention to quit in next 12 months or not interested in quitting; (4) time to first use of smokeless tobacco product within 30 minutes of waking up; and (5) knowledge of smokeless tobacco hazards. RESULTS The number of hardcore smokeless tobacco users among adult Indians is estimated to be 5% (39.5 million). This group comprises 23.2% of daily smokeless tobacco users. The population prevalence varied from 1.4-9.1% across different national regions of India. Logistic regression modeling indicated age, education and employment status to be the major predictors of hardcore smokeless tobacco use in India. CONCLUSIONS The presence of a huge number (39.5 million) of hardcore smokeless tobacco users is a challenge to tobacco control and cancer prevention in India. There is an unmet need for a universal tobacco cessation programme and intensification of anti-tobacco education in communities.
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Hart J. Association between air temperature and deaths due to cancer and heart disease in Alabama. ACTA ACUST UNITED AC 2015. [DOI: 10.7243/2054-9903-2-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Kishore J, Jena PK, Bandyopadhyay C, Swain M, Das S, Banerjee I. Hardcore Smoking in Three South-East Asian Countries: Results from the Global Adult Tobacco Survey. Asian Pac J Cancer Prev 2013; 14:625-30. [DOI: 10.7314/apjcp.2013.14.2.625] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hart J. Land elevation and cancer mortality in u.s. Cities and counties using median elevations derived from geographic information systems. Dose Response 2011; 11:41-8. [PMID: 23550227 DOI: 10.2203/dose-response.11-006.hart] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
There are a number of variables that are correlated with land elevation. Land elevation, and in particular, its surrogate variables such as natural background radiation, can be studied in relation to cancer rates. The present ecological study focuses on three such variables correlated with land elevation: natural background radiation (NBR), oxygen concentration (OC), and barometric pressure (BP). In addition, the study uses a novel approach for determining median land elevation values from which the surrogated variables are estimated. Inverse correlations were observed for NBR while direct correlations were found for OC and BP suggesting the presence of a protective effect with all three variables. Further study is indicated to either verify or refute these findings.
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