title: Elevated expression of the miR-17-92 polycistron and miR-21 in hepadnavirus-associated hepatocellular carcinoma contributes to the malignant phenotype.
abstract: Alterations in microRNA (miRNA) expression in both human and animal models have been linked to many forms of cancer. Such miRNAs, which act directly as repressors of gene expression, have been found to frequently reside in fragile sites and genomic regions associated with cancer. This study describes a miRNA signature for human primary hepatitis B virus-positive human hepatocellular carcinoma. Moreover, two known oncomiRs--miRNAs with known roles in cancer--the miR-17-92 polycistron and miR-21, exhibited increased expression in 100% of primary human and woodchuck hepatocellular carcinomas surveyed. To determine the importance of these miRNAs in tumorigenesis, an in vitro antisense oligonucleotide knockdown model was evaluated for its ability to reverse the malignant phenotype. Both in human and woodchuck HCC cell lines, separate treatments with antisense oligonucleotides specific for either the miR-17-92 polycistron (all six members) or miR-21 caused a 50% reduction in both hepatocyte proliferation and anchorage-independent growth. The combination of assays presented here supports a role for these miRNAs in the maintenance of the malignant transformation of hepatocytes.
authors.affiliation: Marion Bessin Liver Research Center, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Connolly
authors.forename: Margherita
authors.initials: M
authors.lastname: Melegari
authors.forename: Pablo
authors.initials: P
authors.lastname: Landgraf
authors.forename: Tatyana
authors.initials: T
authors.lastname: Tchaikovskaya
authors.forename: Bud C
authors.initials: BC
authors.lastname: Tennant
authors.forename: Betty L
authors.initials: BL
authors.lastname: Slagle
authors.forename: Leslie E
authors.initials: LE
authors.lastname: Rogler
authors.forename: Mihaela
authors.initials: M
authors.lastname: Zavolan
authors.forename: Thomas
authors.initials: T
authors.lastname: Tuschl
authors.forename: Charles E
authors.initials: CE
authors.lastname: Rogler
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015152:Blotting, Northern; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000821:virology; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D005434:Flow Cytometry; D006509:Hepatitis B / Q000235:genetics*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000821:virology; D008392:Marmota; D035683:MicroRNAs / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: C524941:MIRN17 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs