RRC ID 36882
Author Li C, Liu Y, Liu H, Zhang W, Shen C, Cho K, Chen X, Peng F, Bi Y, Hou X, Yang Z, Zheng Z, Wang K, Wang X, Zhang J, Zhong C, Zou H, Zhang X, Zhao S.
Title Impact of autophagy inhibition at different stages on cytotoxic effect of autophagy inducer in glioblastoma cells.
Journal Cell Physiol Biochem
Abstract BACKGROUND/AIMS:Glioblastoma multiforme (GBM) is the most malignant primary brain tumor with a poor prognosis. Combination treatment of autophagy inducer and autophagy inhibitor may be a feasible solution to improve the therapeutic effects. However, the correlation between them is unclear. The purpose of this study was to investigate the effect of autophagy inhibition at different stages on cytotoxicity of autophagy inducers in glioblastoma cells.
METHODS:Autophagy inhibition at early stage was achieved by 3-methyladenine (3-MA) or Beclin 1 shRNA. Autophagy inhibition at late stage was achieved by chloroquine (CQ) or Rab7 shRNA. Cell viability was assessed by MTT assay. Autophagy was measured using transmission electron microscopy and western blot. Apoptosis was measured using western blot and flow-cytometry.
RESULTS:Inhibition of early steps of autophagy by 3-MA or Beclin 1 knockdown decreased the toxic effect of arsenic trioxide (ATO) in GBM cell lines. In contrast, blockade of autophagy flux at late stage by CQ or Rab7 knockdown enhanced the cytotoxicity of ATO, and caused accumulation of degradative autophagic vacuoles and robust apoptosis. Moreover, depletion of Beclin 1 abolished the synergistic effect of ATO and CQ by reducing autophagy and apoptosis. Combination of CQ with other autophagy inducers also induced synergistic apoptotic cell death.
CONCLUSION:These results suggest that inhibition of late process of autophagy, not initial step, increases the cytotoxic effect of autophagy inducers via autophagy and apoptosis, which may contribute to GBM chemotherapy.
Volume 35(4)
Pages 1303-16
Published 2015-1-1
DOI 10.1159/000373952
PII 000373952
PMID 25721868
MeSH Adenine / analogs & derivatives* Adenine / pharmacology Antineoplastic Agents / pharmacology* Apoptosis / drug effects Apoptosis Regulatory Proteins / antagonists & inhibitors Apoptosis Regulatory Proteins / genetics Apoptosis Regulatory Proteins / metabolism Arsenic Trioxide Arsenicals / pharmacology* Autophagy / drug effects* Beclin-1 Blotting, Western Brain Neoplasms / metabolism Brain Neoplasms / pathology Caspase 3 / metabolism Cell Line, Tumor Chloroquine / pharmacology Drug Synergism Flow Cytometry Glioblastoma / metabolism Glioblastoma / pathology Humans Membrane Proteins / antagonists & inhibitors Membrane Proteins / genetics Membrane Proteins / metabolism Microscopy, Electron, Transmission Oxides / pharmacology* RNA Interference RNA, Small Interfering / metabolism rab GTP-Binding Proteins / antagonists & inhibitors rab GTP-Binding Proteins / genetics rab GTP-Binding Proteins / metabolism rab7 GTP-Binding Proteins
IF 5.5
Times Cited 38
Human and Animal Cells U251(RCB0461)