Expression of αb-crystallin overrides the anti-apoptotic activity of XIAP

Cited 13 time in scopus
Metadata Downloads
Title
Expression of αb-crystallin overrides the anti-apoptotic activity of XIAP
Author(s)
J S Lee; H Y Kim; N Y Jeong; S Y Lee; Y G Yoon; Y H Choi; C Yan; In-Sun Chu; H Koh; H T Park; Y H Yoo
Bibliographic Citation
Neuro-Oncology, vol. 14, no. 11, pp. 1332-1345
Publication Year
2012
Abstract
Although crystallins are major structural proteins in the lens, α-crystallins perform non-lens functions, and αB-crystallin has been shown to act as an anti-apoptotic mediator in various cells. The present study was undertaken to examine whether αB-crystallin expressed in human malignant glioma cells exerts anti-apoptotic acitivity. In addition, we sought to elucidate the mechanism underlying any observed anti-apoptotic function of αB-crystallin in these cells. Three glioma cell lines, U373MG, U118MG, and T98G, were used. We observed that only the U373MG cell line expresses αB-crystallin, whereas the other 2 glioma cell lines, U118MG and T98G, demonstrated no endogenous expression of αB-crystallin. We next observed that the silencing of αB-crystallin sensitized U373MG cells to suberoylanilide hydroxamic acid (SAHA)-induced apoptosis and that αB-crystallin associates with caspase-3 and XIAP. Because XIAP is the most potent suppressor of mammalian apoptosis through the direct binding with caspases, we assessed whether XIAP also plays an anti-apoptotic role in SAHA-induced apoptosis in αB-crystallin-expressing U373MG cells. Of note, the silencing of XIAP did not alter the amount of cell death induced by SAHA, indicating that XIAP does not exert an anti-apoptotic activity in U373MG cells. We then determined whether the ectopic expression of αB-crystallin in glioma cells caused a loss of the anti-apoptotic activity of XIAP. Accordingly, we established 2 αB-crystallin over-expressing glioma cell lines, U118MG and T98G, and found that the silencing of XIAP did not sensitize these cells to SAHA-induced apoptosis. These findings suggest that αB-crystallin expressed in glioma cells overrides the anti-apoptotic activity exerted by XIAP.
Keyword
αB-crystallinapoptosisgliomaSAHAXIAP
ISSN
1522-8517
Publisher
Oxford Univ Press
DOI
http://dx.doi.org/10.1093/neuonc/nos247
Type
Article
Appears in Collections:
Division of Biomedical Research > Metabolic Regulation Research Center > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.