title: miR-21 and 221 upregulation and miR-181b downregulation in human grade II-IV astrocytic tumors.
abstract: MicroRNAs (miRNAs) are small noncoding regulatory RNAs that reduce stability and/or translation of fully or partially sequence-complementary target mRNAs. Recent evidence indicates that miRNAs can function both as tumor suppressors and as oncogenes. It has been demonstrated that in glioblastoma multiforme miR-21 and 221 are upregulated whereas miR-128 and 181 are downregulated. Expression of miR-21, 221, 128a, 128b, 128c, 181a, 181b, 181c was studied using real-time quantitative reverse transcriptase polymerase chain reaction and northern blotting for human astrocytic tumors with different grade of malignancy. miR-21 and 221 were overexpressed in glioma samples, whereas miRNA 181b was downregulated compared with normal brain tissue. miRNA-21 was hyperexpressed in all tumor samples whereas higher levels of miRNA-221 were found in high-grade gliomas. This study is the first analysis of miRNAs in astrocytic tumor at different stages of malignancy. The different expression pattern observed in tumors at different stages of malignancy is probably dependent on the cell-specific repertoire of target genes of tumors sharing different molecular pathways activity and suggests miRNAs may have also a place in diagnosis and staging of brain tumors.
authors.affiliation: Department of Neuroscience, A.O.U. Policlinico Universitario, University of Messina, Italy. alfredo.conti@unime.it
authors.forename: Alfredo
authors.initials: A
authors.lastname: Conti
authors.forename: M'Hammed
authors.initials: M
authors.lastname: Aguennouz
authors.forename: Domenico
authors.initials: D
authors.lastname: La Torre
authors.forename: Chiara
authors.initials: C
authors.lastname: Tomasello
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cardali
authors.forename: Filippo F
authors.initials: FF
authors.lastname: Angileri
authors.forename: Francesca
authors.initials: F
authors.lastname: Maio
authors.forename: Annamaria
authors.initials: A
authors.lastname: Cama
authors.forename: Antonino
authors.initials: A
authors.lastname: Germanò
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vita
authors.forename: Francesco
authors.initials: F
authors.lastname: Tomasello
mesh_terms: D000328:Adult; D000368:Aged; D015152:Blotting, Northern; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D015536:Down-Regulation; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D035683:MicroRNAs; C524940:MIRN21 microRNA, human; C525709:MIR221, human; C540193:MIrn181 microRNA, human