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Title: Down-regulation of 14-3-3β exerts anti-cancer effects through inducing ER stress in human glioma U87 cells: Involvement of CHOP–Wnt pathway

We previously identified 14-3-3β as a tumor-specific isoform of 14-3-3 protein in astrocytoma, but its functional role in glioma cells and underlying mechanisms are poorly understood. In the present study, we investigated the effects of 14-3-3β inhibition in human glioma U87 cells using specific targeted small interfering RNA (siRNA). The results showed that 14-3-3β is highly expressed in U87 cells but not in normal astrocyte SVGp12 cells. Knockdown of 14-3-3β by Si-14-3-3β transfection significantly decreased the cell viability but increased the LDH release in a time-dependent fashion in U87 cells, and these effects were accompanied with G0/G1 cell cycle arrest and apoptosis. In addition, 14-3-3β knockdown induced ER stress in U87 cells, as evidenced by ER calcium release, increased expression of XBP1S mRNA and induction of ER related pro-apoptotic factors. Down-regulation of 14-3-3β significantly decreased the nuclear localization of β-catenin and inhibited Topflash activity, which was shown to be reversely correlated with CHOP. Furthermore, Si-CHOP and sFRP were used to inhibit CHOP and Wnt, respectively. The results showed that the anti-cancer effects of 14-3-3β knockdown in U87 cells were mediated by increased expression of CHOP and followed inhibition of Wnt/β-catenin pathway. In summary, the remarkable efficiency of 14-3-3β knockdown tomore » induce apoptotic cell death in U87 cells may find therapeutic application for the treatment of glioma patients. - Highlights: • Knockdown of 14-3-3β leads to cytotoxicity in human glioma U87 cells. • Knockdown of 14-3-3β induces cell cycle arrest and apoptosis in U87 cells. • Knockdown of 14-3-3β results in ER stress in U87 cells. • Knockdown of 14-3-3β inhibits Wnt/β-catenin pathway via CHOP activation.« less
Authors:
; ; ;  [1] ;  [2]
  1. Department of Neurological Disease, Xi'an Central Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710000 (China)
  2. Department of Functional Neurosurgery, Xi'an Red Cross Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710054 (China)
Publication Date:
OSTI Identifier:
22462106
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 462; Journal Issue: 4; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; APOPTOSIS; CALCIUM; CELL CYCLE; EFFICIENCY; GLIOMAS; HUMAN POPULATIONS; INDUCTION; INHIBITION; MESSENGER-RNA; PATIENTS; PROTEINS; STRESSES; TIME DEPENDENCE; TOXICITY; VIABILITY