期刊
JOURNAL OF SURGICAL RESEARCH
卷 163, 期 2, 页码 276-281出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jss.2010.02.021
关键词
autophagy; Bcl-2; BH-3; apoptosis; pancreatic cancer; beclin 1
类别
资金
- Abbott Oncology Laboratories
- NIH [1RO3 CA123004]
- Isabelle J. McDonald Endowment
Background. Bcl-2 is an essential regulator of programmed cell death (PCD). Overexpression of Bcl-2 is common in pancreatic cancer; the high levels have been shown to correlate with resistance to PCD. This resistance is mediated by binding of Bcl-2 via its BH-3 domain to diverse proteins, including the Bax/Bak family members, various protein kinases, and beclin 1, which are involved in regulation of autophagy (type II PCD). Small molecule inhibitors of BH-3-mediated binding of Bcl-2 have been recently developed, although no investigation has been conducted in pancreatic cancer, a malignancy characterized by extreme resistance to PCD. Methods. The effect of the Bcl-2 binding inhibitor A-779024 on PCD was assessed by fluorescence activated cell sorting; the effect on Bcl-2 and other PCD-related proteins was analyzed by immunoblotting. Induction of autophagy was determined by fluorescence microscopy using a stably transfected GFP-LC3 construct to visualize autophagosome formation. Co-localization of Bcl-2 with binding partners regulating PCD was examined by immunoprecipitation and confocal immunofluorescent microscopy. Results. A-779024 induced PCD in a dose- and time-dependent fashion. No change was seen in the protein levels of Bcl-2, Bax, Bcl-XL, or Mcl-1. Contrary to prediction, A-779024 was ineffective at inducing autophagy in these cells. Co-localization studies demonstrated that Bcl-2 was not bound to beclin 1 and, therefore, treatment with A-779024 could not induce release of beclin 1 and initiation of autophagy. Conclusions. Disruption of Bcl-2 activity using the small molecule inhibitor A-779024 induces apoptotic but not autophagic PCD. This approach may be a novel therapy, either alone or in combination with other treatments such as chemotherapy or autophagy modulating agents in pancreatic cancer. (C) 2010 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据