title: Epigenetic Repression of miR-218 Promotes Esophageal Carcinogenesis by Targeting ROBO1.
abstract: miR-218, consisting of miR-218-1 at 4p15.31 and miR-218-2 at 5q35.1, was significantly decreased in esophageal squamous cell carcinoma (ESCC) in our previous study. The aim of this study was to determine whether aberrant methylation is associated with miR-218 repression. Bisulfite sequencing analysis (BSP), methylation specific PCR (MSP), and 5-aza-2'-deoxycytidine treatment assay were applied to determine the methyaltion status of miR-218 in cells and clinical samples. In vitro assays were performed to explore the role of miR-218. Results showed that miR-218-1 was significantly CpG hypermethylated in tumor tissues (81%, 34/42) compared with paired non-tumor tissues (33%, 14/42) (p < 0.05). However, no statistical difference was found in miR-218-2. Accordingly, expression of miR-218 was negatively correlated with miR-218-1 methylation status (p < 0.05). After demethylation treatment by 5-aza-2'-deoxycytidine, there was a 2.53- and 2.40-fold increase of miR-218 expression in EC109 and EC9706, respectively. miR-218 suppressed cell proliferation and arrested cells at G1 phase by targeting 3' untranslated region (3'UTR) of roundabout guidance receptor 1 (ROBO1). A negative correlation was found between miR-218 and ROBO1 mRNA expression in clinical samples. In conclusion, our results support that aberrant CpG hypermethylation at least partly accounts for miR-218 silencing in ESCC, which impairs its tumor-suppressive function.
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. 230129498@seu.edu.cn.
authors.forename: Miao
authors.initials: M
authors.lastname: Yang
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. ranliu@seu.edu.cn.
authors.forename: Ran
authors.initials: R
authors.lastname: Liu
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. 220122800@seu.edu.cn.
authors.forename: Xiajun
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. 230129495@seu.edu.cn.
authors.forename: Juan
authors.initials: J
authors.lastname: Liao
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. yppu@seu.edu.cn.
authors.forename: Yuepu
authors.initials: Y
authors.lastname: Pu
authors.affiliation: Huaian Center for Disease Control and Prevention, Huaian 223001, China. hypec@163.com.
authors.forename: Enchun
authors.initials: E
authors.lastname: Pan
authors.affiliation: Huaian Center for Disease Control and Prevention, Huaian 223001, China. wangyihuaian@163.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. lhyin@seu.edu.cn.
authors.forename: Lihong
authors.initials: L
authors.lastname: Yin
mesh_terms: D020413:3' Untranslated Regions; D001374:Azacitidine / Q000494:pharmacology; D001483:Base Sequence; D001665:Binding Sites; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D018899:CpG Islands; D019175:DNA Methylation; D063185:Epigenetic Repression; D004938:Esophageal Neoplasms / Q000235:genetics*; D000077277:Esophageal Squamous Cell Carcinoma; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D023061:Gene Order; D056426:Genetic Loci; D006801:Humans; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D034622:RNA Interference; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D011971:Receptors, Immunologic / Q000235:genetics*; D000097905:Roundabout Proteins
chemical_list: D020413:3' Untranslated Regions; D001374:Azacitidine; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins; C547471:MIRN218 microRNA, human
keywords: CpG methylation; ROBO1; esophageal cancer; miR-218