title: The micro-RNA 199b-5p regulatory circuit involves Hes1, CD15, and epigenetic modifications in medulloblastoma.
abstract: Micro-RNA (miR) 199b-5p targets Hes1 in medulloblastoma, one of the downstream effectors of both the canonical Notch and noncanonical Sonic Hedgehog pathways. In medulloblastoma patients, expression of miR-199b-5p is significantly decreased in metastatic cases, thus suggesting a downregulation mechanism. We studied this mechanism, which is mediated mostly by Hes1 and epigenetic promoter modifications. The miR-199b-5p promoter region was characterized, which identified a Hes1 binding site, thus demonstrating a negative feedback loop of regulation. MiR-199b-5p was shown to be downregulated in several medulloblastoma cell lines and in tumors by epigenetic methylation of a cytosine-phosphate-guanine island upstream of the miR-199b-5p promoter. Furthermore, the cluster of differention (CD) carbohydrate antigen CD15, a marker of medulloblastoma tumor-propagating cells, is an additional direct target of miR-199b-5p. Most importantly, regulation of miR-199b-5p expression in these CD15+/CD133+ tumor-propagating cells was influenced by only Hes1 expression and not by any epigenetic mechanism of regulation. Moreover, reverse-phase protein array analysis showed both the Akt and extracellular-signal-regulated kinase pathways as being mainly negatively regulated by miR-199b-5p expression in several medulloblastoma cell lines and in primary cell cultures. We present here the finely tuned regulation of miR-199b-5p in medulloblastoma, underlining its crucial role by its additional targeting of CD15.
authors.affiliation: CEINGE, Biotecnologie Avanzate, Naples, Italy.
authors.forename: Immacolata
authors.initials: I
authors.lastname: Andolfo
authors.forename: Lucia
authors.initials: L
authors.lastname: Liguori
authors.forename: Pasqualino
authors.initials: P
authors.lastname: De Antonellis
authors.forename: Emilio
authors.initials: E
authors.lastname: Cusanelli
authors.forename: Federica
authors.initials: F
authors.lastname: Marinaro
authors.forename: Francesca
authors.initials: F
authors.lastname: Pistollato
authors.forename: Livia
authors.initials: L
authors.lastname: Garzia
authors.forename: Gennaro
authors.initials: G
authors.lastname: De Vita
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Petrosino
authors.forename: Benedetta
authors.initials: B
authors.lastname: Accordi
authors.forename: Roberta
authors.initials: R
authors.lastname: Migliorati
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Basso
authors.forename: Achille
authors.initials: A
authors.lastname: Iolascon
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cinalli
authors.forename: Massimo
authors.initials: M
authors.lastname: Zollo
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D049109:Cell Proliferation; D002478:Cells, Cultured; D002528:Cerebellar Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002675:Child, Preschool; D047369:Chromatin Immunoprecipitation; D018899:CpG Islands; D019175:DNA Methylation; D057890:Epigenomics; D005260:Female; D005434:Flow Cytometry; D005647:Fucosyltransferases / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D016256:Lewis X Antigen / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008527:Medulloblastoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D061251:Primary Cell Culture; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D000072056:Transcription Factor HES-1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D005647:Fucosyltransferases; D018398:Homeodomain Proteins; D016256:Lewis X Antigen; D035683:MicroRNAs; D012333:RNA, Messenger; D000072056:Transcription Factor HES-1; C531408:mirn199 microRNA, human; C078493:HES1 protein, human; C066693:FUT4 protein, human