title: Mechanism of temozolomide-induced antitumour effects on glioma cells.
abstract: OBJECTIVE
  To investigate the mechanisms of action of the tumoricidal effects of temozolomide against the human glioma cell line U251 in vitro, and to provide preclinical proof-of-concept studies of the effects of temozolomide-containing regimens.
  
  
  METHODS
  U251 cells were exposed to 100 µmol/l temozolomide. Morphological alterations were monitored by light microscopy. Cell viability was measured using the 3 -(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle analysis and the rate of apoptosis were determined using flow cytometry and the number of acidic vesicular organelles stained with acridine orange were analysed by fluorescence microscopy. The scratch recovery test was used to measure cell migration.
  
  
  RESULTS
  U251 cells that were treated with temozolomide displayed morphological alterations indicative of a rounder shape and impaired cellular adhesion to the cell culture plate compared with control U251 cells. Temozolomide reduced cell viability as measured by the MTT assay, caused cell cycle arrest in the gap 2/mitosis phase, inhibited cell migration and promoted autophagy in U251 cells.
  
  
  CONCLUSIONS
  Temozolomide induced autophagic, but not apoptotic processes, in U251 cells and thus reduced their viability and migration.
authors: Department of Neurosurgery, Beilun People's Hospital, Ningbo, Zhejiang Province, China.
authors: Wei
authors: W
authors: Shen
authors: Jun-An
authors: JA
authors: Hu
authors: Jie-Sheng
authors: JS
authors: Zheng
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D001932:Brain Neoplasms / Q000473:pathology*; D002453:Cell Cycle; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005434:Flow Cytometry; D005910:Glioma / Q000473:pathology*; D006801:Humans; D020128:Inhibitory Concentration 50; D008856:Microscopy, Fluorescence; D000077204:Temozolomide
chemical_list: D000970:Antineoplastic Agents; D003606:Dacarbazine; D000077204:Temozolomide
keywords: Glioma; apoptosis; autophagy; cell culture; flow cytometry; in vitro study; temozolomide