title: MicroRNA-145 ModulatesN6-Methyladenosine Levels by Targeting the 3'-Untranslated mRNA Region of theN6-Methyladenosine Binding YTH Domain Family 2 Protein.
abstract: N6-Methyladenosine (m6A) is a prevalent modification present in the mRNAs of higher eukaryotes. YTH domain family 2 (YTHDF2), an m6A "reader" protein, can recognize mRNA m6A sites to mediate mRNA degradation. However, the regulatory mechanism of YTHDF2 is poorly understood. To this end, we investigated the post-transcriptional regulation of YTHDF2. Bioinformatics analysis suggested that the microRNA miR-145 might target the 3'-untranslated region (3'-UTR) of YTHDF2 mRNA. The levels of miR-145 were negatively correlated with those of YTHDF2 mRNA in clinical hepatocellular carcinoma (HCC) tissues, and immunohistochemical staining revealed that YTHDF2 was closely associated with malignancy of HCC. Interestingly, miR-145 decreased the luciferase activities of 3'-UTR of YTHDF2 mRNA. Mutation of predicted miR-145 binding sites in the 3'-UTR of YTHDF2 mRNA abolished the miR-145-induced decrease in luciferase activity. Overexpression of miR-145 dose-dependently down-regulated YTHDF2 expression in HCC cells at the levels of both mRNA and protein. Conversely, inhibition of miR-145 resulted in the up-regulation of YTHDF2 in the cells. Dot blot analysis and immunofluorescence staining revealed that the overexpression of miR-145 strongly increased m6A levels relative to those in control HCC cells, and this increase could be blocked by YTHDF2 overexpression. Moreover, miR-145 inhibition strongly decreased m6A levels, which were rescued by treatment with a small interfering RNA-based YTHDF2 knockdown. Thus, we conclude that miR-145 modulates m6A levels by targeting the 3'-UTR of YTHDF2 mRNA in HCC cells.
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yang
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Guoxing
authors.initials: G
authors.lastname: Feng
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Shuqin
authors.initials: S
authors.lastname: Zhang
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071, China, and.
authors.forename: Lihong
authors.initials: L
authors.lastname: Ye
authors.affiliation: Department of Clinical Laboratory, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China yli08@tmu.edu.cn.
authors.forename: Yueguo
authors.initials: Y
authors.lastname: Li
authors.affiliation: From the State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China, zhangxd@nankai.edu.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D020413:3' Untranslated Regions; D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry; D006528:Carcinoma, Hepatocellular / Q000378:metabolism; D049109:Cell Proliferation; D015536:Down-Regulation; D056945:Hep G2 Cells; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D000072417:Protein Domains; D034741:RNA, Small Interfering / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C000600306:YTHDF1 protein, human; C585900:YTHDF2 protein, human; C010223:N-methyladenosine; D000241:Adenosine
keywords: N6-methyladenosine (m6A); RNA methylation; RNA modification; YTH domain family 2 (YTHDF2); mRNA decay; mRNA degradation; miR-145; microRNA (miRNA); microRNA mechanism