title: MicroRNA-21 inhibition enhances in vitro chemosensitivity of temozolomide-resistant glioblastoma cells.
abstract: BACKGROUND
  Glioblastoma multiforme (GBM) is a form of highly malignant brain tumour. Temozolomide (TMZ) is the standard agent for GBM, but TMZ-resistance is common and accounts for many treatment failures. MicroRNA-21 (miR-21) is a non-coding RNA that plays critical roles in many biological processes in cancer, including chemoresistance. We investigated miR-21 expression and the effect of miR-21 inhibition in GBM with acquired TMZ resistance.
  
  
  METHODS
  Human GBM cell line D54MG was treated with TMZ chronically to develop a chemoresistant subclone. MiR-21 inhibition was achieved by transfection with anti-mir-21 oligonucleotide.
  
  
  RESULTS
  Chronic TMZ exposure resulted in acquired TMZ-resistance and elevated miR-21 expression. Concomitant treatment with miR-21 inhibitor and TMZ resulted in a significantly higher apoptotic rate than TMZ treatment alone.
  
  
  CONCLUSIONS
  MiR-21 may have a potential for use as a biomarker of acquired TMZ resistance. MiR-21 inhibition can be further explored as a potential chemotherapy adjunct in the treatment of TMZ-resistant GBM.
authors: Division of Neurosurgery, Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, 102, Pokfulam Road, Hong Kong, PRC.
authors: Stanley Thian Sze
authors: ST
authors: Wong
authors: Xiao-Qin
authors: XQ
authors: Zhang
authors: James Tin-Fong
authors: JT
authors: Zhuang
authors: Hin-Lun
authors: HL
authors: Chan
authors: Chi-Han
authors: CH
authors: Li
authors: Gilberto Ka Kit
authors: GK
authors: Leung
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000235:genetics; D001932:Brain Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000628:therapy*; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015316:Genetic Therapy; D005909:Glioblastoma / Q000188:drug therapy / Q000235:genetics / Q000628:therapy*; D006801:Humans; D035683:MicroRNAs / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage* / Q000235:genetics; D000077204:Temozolomide; D014162:Transfection
chemical_list: D018906:Antineoplastic Agents, Alkylating; D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D003606:Dacarbazine; D000077204:Temozolomide