title: Let-7 microRNA inhibits the proliferation of human glioblastoma cells.
abstract: MicroRNAs (miRNAs) are small noncoding RNAs comprising 21-23 nucleotides that regulate gene expression by transcriptionally repressing their complementary mRNAs. In particular, let-7 miRNA has been postulated to function as a tumor suppressor in various cancer cells, but not yet in glioblastoma. In this study, we investigated the anti-tumorigenic effect of let-7 miRNA in glioblastoma cells. Human glioblastoma cells (U251 or U87 cells) were transfected with let-7 miRNA and assayed for in-vitro proliferation, migration, and in-vivo tumor formation. Transfection of let-7 miRNA reduced expression of pan-RAS, N-RAS, and K-RAS in the glioblastoma cells. Let-7 miRNA also reduced the in-vitro proliferation and migration of the cells, and reduced the sizes of the tumors produced after transplantation into nude mice. However, let-7 miRNA exerted no effect on the proliferation of normal human astrocytes. These results indicate that let-7 miRNA has an anti-tumorigenic effect on glioblastoma cells, and suggest possible use of let-7 miRNA for treating glioblastoma.
authors.affiliation: Department of Neurology, Clinical Research Institute, Seoul National University Hospital, 101, Daehangno, Jongno-Gu, Seoul 110-744, South Korea.
authors.forename: Soon-Tae
authors.initials: ST
authors.lastname: Lee
authors.forename: Kon
authors.initials: K
authors.lastname: Chu
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Oh
authors.forename: Woo-Seok
authors.initials: WS
authors.lastname: Im
authors.forename: Ji-Yeon
authors.initials: JY
authors.lastname: Lim
authors.forename: Seung-Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: Cheol-Ki
authors.initials: CK
authors.lastname: Park
authors.forename: Keun-Hwa
authors.initials: KH
authors.lastname: Jung
authors.forename: Sang Kun
authors.initials: SK
authors.lastname: Lee
authors.forename: Manho
authors.initials: M
authors.lastname: Kim
authors.forename: Jae-Kyu
authors.initials: JK
authors.lastname: Roh
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D018631:ras Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; C487931:mirnlet7 microRNA, human; D018631:ras Proteins