title: Light at night and melatonin have opposite effects on breast cancer tumors in mice assessed by growth rates and global DNA methylation.
abstract: Light-at-night (LAN) is a worldwide problem co-distributed with breast cancer prevalence. We hypothesized that exposure to LAN is coincided with a decreased melatonin (MLT) secretion level, followed by epigenetic modifications and resulted in higher breast cancer tumors growth-rate. Accordingly, we studied the effect of LAN exposure and exogenous MLT on breast cancer tumors growth-rate. 4T1 cells were inoculated into BALB/c short day-acclimated mice, resulting in tumors growth. Growth rates were followed under various light exposures and global DNA methylations were measured. Results demonstrated the positive effect of LAN on tumors growth-rate, reversed by MLT through global DNA methylation.
authors.affiliation: The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa , Mount Carmel, Haifa , Israel .
authors.forename: Hagit
authors.initials: H
authors.lastname: Schwimmer
authors.forename: Avishag
authors.initials: A
authors.lastname: Metzer
authors.forename: Yonit
authors.initials: Y
authors.lastname: Pilosof
authors.forename: Moshe
authors.initials: M
authors.lastname: Szyf
authors.forename: Ziv M
authors.initials: ZM
authors.lastname: Machnes
authors.forename: Fuad
authors.initials: F
authors.lastname: Fares
authors.forename: Orna
authors.initials: O
authors.lastname: Harel
authors.forename: Abraham
authors.initials: A
authors.lastname: Haim
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D008027:Light; D008325:Mammary Neoplasms, Experimental / Q000209:etiology / Q000473:pathology*; D008550:Melatonin / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000652:urine; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D017440:Photoperiod; D010870:Pineal Gland / Q000378:metabolism; D015398:Signal Transduction
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin