title: MicroRNA-141 and microRNA-146b-5p inhibit the prometastatic mesenchymal characteristics through the RNA-binding protein AUF1 targeting the transcription factor ZEB1 and the protein kinase AKT.
abstract: miR-141 and miR-146b-5p are two important tumor suppressor microRNAs, which control several cancer-related genes and processes. In the present report, we have shown that these microRNAs bind specific sites at the 3'-untranslated region (UTR) of the mRNA-binding protein AUF1, leading to its down-regulation. This inverse correlation between the levels of these microRNAs and AUF1 has been identified in various osteosarcoma cell lines. Additionally, we present clear evidence that AUF1 promotes mesenchymal features in osteosarcoma cells and that miR-141 and miR-146b-5p suppress this prometastatic process through AUF1 repression. Indeed, both microRNAs suppressed the invasion/migration and proliferation abilities of osteosarcoma cells through inhibiting the AKT protein kinase in an AUF1-dependent manner. We have also shown that AUF1 binds to and stabilizes the mRNA of the AKT activator phosphoinositide-dependent kinase-1 (PDK1). Furthermore, miR-141 and miR-146b-5p positively regulate the epithelial markers (E-cadherin and Epcam) and repress the mesenchymal markers (N-cadherin, Vimentin, Twist2, and ZEB1). These effects were mediated via the repression of the epithelial-to-mesenchymal inducer ZEB1 through targeting AUF1, which binds the 3'-UTR of the ZEB1 mRNA and reduces its turnover. These results indicate that at least some tumor suppressor functions of miR-141 and miR-146b-5p are mediated through the repression of the oncogenic potentials of AUF1. Therefore, these 3'-UTR-directed post-transcriptional gene expression regulators constitute promising new targets for diagnostic and/or therapeutic interventions.
authors.affiliation: From the Department of Molecular Oncology, King Faisal Specialist Hospital and Research Centre, MBC 03, P.O. Box 3354, Riyadh 11211, Saudi Arabia and the Joint Center for Genomics Research, King Abdulaziz City for Science and Technology, Riyadh 11211, Saudi Arabia.
authors.forename: Huda H
authors.initials: HH
authors.lastname: Al-Khalaf
authors.affiliation: From the Department of Molecular Oncology, King Faisal Specialist Hospital and Research Centre, MBC 03, P.O. Box 3354, Riyadh 11211, Saudi Arabia and aboussekhra@kfshrc.edu.sa.
authors.forename: Abdelilah
authors.initials: A
authors.lastname: Aboussekhra
mesh_terms: D020413:3' Untranslated Regions; D001483:Base Sequence; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D / Q000737:chemistry* / Q000502:physiology; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D008648:Mesoderm / Q000166:cytology; D035683:MicroRNAs / Q000502:physiology*; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000378:metabolism; D011379:Prognosis; D011485:Protein Binding; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism*; D000071799:Zinc Finger E-box-Binding Homeobox 1
chemical_list: D020413:3' Untranslated Regions; C000630986:HNRNPD protein, human; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D; D018398:Homeodomain Proteins; C533895:MIRN141 microRNA, human; C542542:MIRN146 microRNA, human; D035683:MicroRNAs; D014157:Transcription Factors; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1; D051057:Proto-Oncogene Proteins c-akt
keywords: AKT; AUF1; Cell Invasion; Cell Migration; Epithelial-Mesenchymal Transition (EMT); Post-transcriptional Regulation; RNA-binding Protein; ZEB1; miR-141; miR-146b-5p