title: Expression of members of the miRNA17-92 cluster during development and in carcinogenesis.
abstract: The six microRNAs (miRNA) encoded by the miR-17-92 cluster, also named oncomir-1, have been associated with carcinogenesis and typically exhibit-increased expression in tumors. Despite the well-established role for the miR-17-92 cluster in an oncogenic network, the physiological function of these miRNAs in normal tissues remains unresolved. In order to investigate whether there are similar patterns of miR-17-92 expression during embryogenesis and carcinogenesis, we have preformed a systematic study of the expression in cultured carcinoma cells, cultured primary human keratinocytes (KC), and during development of some murine tissues. Both levels of expression of the primary transcript (pri-miRNA) and levels of expression of the individual members of the cluster were monitored. Irrespectively of tissue examined we found that the level of expression decreased markedly during development. With cultured primary human KCs their levels of expression of some of these microRNAs decreased as the number of cell passages increased. Their levels of expression in cultured carcinoma cells, in contrasts, increased, or remained unchanged, with increasing number of cell passages. The results suggest these microRNAs are involved in the regulation of foetal development and that they may promote proliferation and inhibit differentiation during embryogenesis and carcinogenesis. Additionally, the six microRNAs exhibit variable tissue expression, suggesting selective processing of these microRNAs.
authors.affiliation: Department of Oral Biology, University of Oslo, Blindern, Oslo, Norway. a.m.jevnaker@odont.uio.no
authors.forename: Anne-Marthe
authors.initials: AM
authors.lastname: Jevnaker
authors.forename: Cuong
authors.initials: C
authors.lastname: Khuu
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kjøle
authors.forename: Magne
authors.initials: M
authors.lastname: Bryne
authors.forename: Harald
authors.initials: H
authors.lastname: Osmundsen
mesh_terms: D000818:Animals; D002460:Cell Line; D004622:Embryo, Mammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism; D008099:Liver / Q000196:embryology / Q000378:metabolism; D008168:Lung / Q000196:embryology / Q000378:metabolism; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D005810:Multigene Family / Q000235:genetics*; D009928:Organ Specificity / Q000235:genetics; D011230:Precancerous Conditions / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012469:Salivary Glands / Q000196:embryology / Q000378:metabolism; D014083:Tooth Germ / Q000196:embryology / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger