title: MicroRNA-124a is epigenetically regulated and acts as a tumor suppressor by controlling multiple targets in uveal melanoma.
abstract: OBJECTIVE
  MicroRNA-124a (miR-124a), an abundant microRNA in the central neuron system, has been linked to tumor progression. Here, we investigated the role of miR-124a in uveal melanoma development.
  
  
  METHODS
  Expression of miR-124a in uveal melanoma cells was examined using real time RT-PCR. The effect of miR-124a on cell proliferation, migration, and invasion was analyzed using MTS assay, flow cytometry, and transwell experiments. The ability of miR-124a to repress tumor growth was tested in vivo. Target genes of miR-124a were first predicted by bioinformatics, confirmed using a luciferase assay, and their expression determined by Western blotting. DNA methylation and histone modification of miR-124a was analyzed by methylation-specific PCR and ChIP assay. Finally, epigenetic drugs were used to alter the expression of miR-124a.
  
  
  RESULTS
  miR-124a expression was downregulated in both uveal melanoma cells and clinical specimens. Transient transfection of miR-124a into uveal melanoma cells inhibited cell growth, migration, and invasion. Moreover, introduction of miR-124a suppressed in vivo growth of tumor. Potential targets of miR-124a were found to include CDK4, CDK6, cyclin D2, and EZH2. Knockdown of EZH2 by siRNA resulted in inhibition of uveal melanoma cell migration and invasion. In addition, miR-124a expression was found to be regulated via epigenetic mechanisms, with its expression restored when cells were treated with a DNA hypomethylating agent, 5-aza-2'-deoxycytidine, and a histone deacetylase inhibitor, trichostatin A.
  
  
  CONCLUSIONS
  Our results demonstrated that miR-124a could function as a potent tumor suppressor by regulation of multiple targets, and was epigenetically silenced in the development of uveal melanoma.
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China.
authors: Xiaoyan
authors: X
authors: Chen
authors: Dandan
authors: D
authors: He
authors: Xiang Da
authors: XD
authors: Dong
authors: Feng
authors: F
authors: Dong
authors: Jiao
authors: J
authors: Wang
authors: Lihua
authors: L
authors: Wang
authors: Jiang
authors: J
authors: Tang
authors: Dan-Ning
authors: DN
authors: Hu
authors: Dongsheng
authors: D
authors: Yan
authors: LiLi
authors: L
authors: Tu
mesh_terms: D015153:Blotting, Western; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D019175:DNA Methylation / Q000502:physiology; D015536:Down-Regulation; D044127:Epigenesis, Genetic / Q000502:physiology*; D005134:Eye Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D035683:MicroRNAs / Q000378:metabolism / Q000502:physiology*; D009361:Neoplasm Invasiveness; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000378:metabolism / Q000502:physiology*; D014604:Uveal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000098943:Uveal Melanoma
chemical_list: C509207:MIRN124 microRNA, human; D035683:MicroRNAs; D025521:Tumor Suppressor Proteins