title: Genome-wide profiling in melatonin-exposed human breast cancer cell lines identifies differentially methylated genes involved in the anticancer effect of melatonin.
abstract: Epigenetic alterations have emerged as an important mechanism involved in tumorigenesis. The epigenetic impact of DNA methylation in various types of human cancer is not completely understood. Previously, we observed melatonin-induced differential expression of miRNA and miRNA-related genes in human breast cancer cell lines that indicated an anticancer effect of melatonin. In this report, we further characterized epigenetic changes in melatonin-exposed MCF-7 cells through the analysis of DNA methylation profiles in breast cancer cells to provide new insights into the potential mechanisms of the anticancer effect of melatonin. Microarray-based DNA methylation and gene expression profiling were carried out using human breast cancer cell lines. We further identified a number of mRNAs whose expression levels show an inverse correlation with DNA methylation levels. The mRNA expression levels and methylation status of candidate genes in melatonin-exposed cells were confirmed by real-time quantitative PCR and bisulfite PCR. This approach led to the detection of cancer-related genes, which were oncogenic genes, including EGR3 and POU4F2/Brn-3b were down-regulated, while the tumor suppressor gene, GPC3, was up-regulated by 1 nm melatonin-treated MCF-7 cells. Our results provide detailed insights into the DNA methylation patterns induced by melatonin and suggest a potential mechanism of the anticancer effect of aberrant DNA methylation in melatonin-treated breast cancer cells.
authors.affiliation: Department of Microbiology, School of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Seung Eun
authors.initials: SE
authors.lastname: Lee
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Kim
authors.forename: Hyo-Jeong
authors.initials: HJ
authors.lastname: Yoon
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Yu
authors.forename: Hana
authors.initials: H
authors.lastname: Yang
authors.forename: Seong Il
authors.initials: SI
authors.lastname: Jeong
authors.forename: Seung Yong
authors.initials: SY
authors.lastname: Hwang
authors.forename: Cheung-Seog
authors.initials: CS
authors.lastname: Park
authors.forename: Yong Seek
authors.initials: YS
authors.lastname: Park
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D045744:Cell Line, Tumor; D019175:DNA Methylation / Q000187:drug effects; D015536:Down-Regulation; D051776:Early Growth Response Protein 3 / Q000235:genetics; D044127:Epigenesis, Genetic / Q000187:drug effects; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D063990:Gene Ontology; D016147:Genes, Tumor Suppressor / Q000187:drug effects; D053673:Glypicans / Q000235:genetics; D006801:Humans; D008550:Melatonin / Q000627:therapeutic use*; D009857:Oncogenes / Q000187:drug effects*; D050820:Transcription Factor Brn-3B / Q000235:genetics; D015854:Up-Regulation
chemical_list: D000970:Antineoplastic Agents; C079945:EGR3 protein, human; C105937:GPC3 protein, human; D053673:Glypicans; C494190:POU4F2 protein, human; D050820:Transcription Factor Brn-3B; D051776:Early Growth Response Protein 3; D008550:Melatonin