title: Artificial light at night: melatonin as a mediator between the environment and epigenome.
abstract: The adverse effects of excessive use of artificial light at night (ALAN) are becoming increasingly evident and associated with several health problems including cancer. Results of epidemiological studies revealed that the increase in breast cancer incidents co-distribute with ALAN worldwide. There is compiling evidence that suggests that melatonin suppression is linked to ALAN-induced cancer risks, but the specific genetic mechanism linking environmental exposure and the development of disease is not well known. Here we propose a possible genetic link between environmental exposure and tumorigenesis processes. We discuss evidence related to the relationship between epigenetic remodelling and oncogene expression. In breast cancer, enhanced global hypomethylation is expected in oncogenes, whereas in tumour suppressor genes local hypermethylation is recognized in the promoter CpG chains. A putative mechanism of action involving epigenetic modifications mediated by pineal melatonin is discussed in relation to cancer prevalence. Taking into account that ALAN-induced epigenetic modifications are reversible, early detection of cancer development is of great significance in the treatment of the disease. Therefore, new biomarkers for circadian disruption need to be developed to prevent ALAN damage.
authors.affiliation: The Israeli Center for Interdisciplinary Research in Chronobiology, Department of Evolutionary and Environmental Biology, University of Haifa, Mount Carmel, Haifa 31905, Israel ahaim@research.haifa.ac.il.
authors.forename: Abraham
authors.initials: A
authors.lastname: Haim
authors.affiliation: The Israeli Center for Interdisciplinary Research in Chronobiology, Department of Evolutionary and Environmental Biology, University of Haifa, Mount Carmel, Haifa 31905, Israel.
authors.forename: Abed E
authors.identifier: http://orcid.org/0000-0002-5649-1086
authors.initials: AE
authors.lastname: Zubidat
mesh_terms: D002940:Circadian Rhythm; D004784:Environmental Monitoring; D004787:Environmental Pollution; D044127:Epigenesis, Genetic; D057890:Epigenomics; D005786:Gene Expression Regulation / Q000528:radiation effects*; D006801:Humans; D008029:Lighting / Q000009:adverse effects*; D008550:Melatonin / Q000378:metabolism*
chemical_list: D008550:Melatonin
keywords: breast cancer; epigenetic modifications; light pollution; melatonin