title: Comparison of microRNA expression levels between initial and recurrent glioblastoma specimens.
abstract: Glioblastoma is the most frequent primary brain tumour in adults. Recent therapeutic advances increased patient's survival, but tumour recurrence inevitably occurs. The pathobiological mechanisms involved in glioblastoma recurrence are still unclear. MicroRNAs are small RNAs proposed o have important roles for cancer including proliferation, aggressiveness and metastases development. There exist only few data on the involvement of microRNAs in glioblastoma recurrence. We selected the following 7 microRNAs with potential relevance for glioblastoma pathobiology by means of a comprehensive literature search: microRNA-10b, microRNA-21, microRNA-181b, microRNA-181c, microRNA-195, microRNA-221 and microRNA-222. We further selected 15 primary glioblastoma patients, of whom formalin fixed and paraffin embedded tissue (FFPE) of the initial and recurrence surgery were available. All patients had received first line treatment consisting of postoperative combined radiochemotherapy with temozolomide (n = 15). Non-neoplastic brain tissue samples from 3 patients with temporal lobe epilepsy served as control. The expression of the microRNAs were analysed by RT-qPCR. These were correlated with each other and with clinical parameters. All microRNAs showed detectable levels of expressions in glioblastoma group, whereas microRNA-10b was not detectable in epilepsy patients. MicroRNAs except microRNA-21 showed significantly higher levels in epilepsy patients when compared to the levels of first resection of glioblastoma. Comparison of microRNA levels between first and second resections revealed no significant change. Cox regression analyses showed no significant association of microRNA expression levels in the tumor tissue with progression free survival times. Expression levels of microRNA-10b, microRNA-21, microRNA-181b, microRNA-181c, microRNA-195, microRNA-221 and microRNA-222 do not differ significantly between initial and recurrent glioblastoma.
authors: Department of Medicine I/Oncology, Medical University of Vienna, Vienna, Austria.
authors: Aysegül
authors: A
authors: Ilhan-Mutlu
authors: Adelheid
authors: A
authors: Wöhrer
authors: Anna Sophie
authors: AS
authors: Berghoff
authors: Georg
authors: G
authors: Widhalm
authors: Christine
authors: C
authors: Marosi
authors: Ludwig
authors: L
authors: Wagner
authors: Matthias
authors: M
authors: Preusser
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D005260:Female; D005909:Glioblastoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs