Complementary Cell-Based High-Throughput Screens Identify Novel Modulators of the Unfolded Protein Response

Author:

Fribley Andrew M.1,Cruz Patricia G.2,Miller Justin R.1,Callaghan Michael U.1,Cai Peter3,Narula Neha3,Neubig Richard R.24,Showalter Hollis D.5,Larsen Scott D.5,Kirchhoff Paul D.5,Larsen Martha J.2,Burr Douglas A.6,Schultz Pamela J.2,Jacobs Renju R.2,Tamayo-Castillo Giselle7,Ron David8,Sherman David H.25,Kaufman Randal J.9

Affiliation:

1. Wayne State University, Carmen and Ann Adams Department of Pediatrics, Division of Hematology/Oncology, Detroit, Michigan

2. University of Michigan, Life Sciences Institute, Life Sciences Institute and Center for Chemical Genomics, Ann Arbor, Michigan

3. Wayne State University, School of Medicine, Detroit, Michigan

4. Department of Pharmacology, Ann Arbor, Michigan University of Michigan, Department of Pharmacology, Ann Arbor, Michigan

5. University of Michigan, College of Pharmacy, Department of Medicinal Chemistry, Ann Arbor, Michigan

6. PerkinElmer, Inc., Boston, MA

7. University of Costa Rica, National Institute for Biodiversity (INBio), Santo Domingo de Heredia, Costa Rica

8. University of Cambridge Institute of Metabolic Science, Cambridge, United Kingdom

9. University of Michigan, Departments of Biological Chemistry and Internal Medicine, Ann Arbor, Michigan

Abstract

Despite advances toward understanding the prevention and treatment of many cancers, patients who suffer from oral squamous cell carcinoma (OSCC) confront a survival rate that has remained unimproved for more than 2 decades, indicating our ability to treat them pharmacologically has reached a plateau. In an ongoing effort to improve the clinical outlook for this disease, we previously reported that an essential component of the mechanism by which the proteasome inhibitor bortezomib (PS-341, Velcade) induced apoptosis in OSCC required the activation of a terminal unfolded protein response (UPR). Predicated on these studies, the authors hypothesized that high-throughput screening (HTS) of large diverse chemical libraries might identify more potent or selective small-molecule activators of the apoptotic arm of the UPR to control or kill OSCC. They have developed complementary cell-based assays using stably transfected CHO-K1 cell lines that individually assess the PERK/eIF2α/CHOP (apoptotic) or the IRE1/XBP1 (adaptive) UPR subpathways. An ˜66 K compound collection was screened at the University of Michigan Center for Chemical Genomics that included a unique library of prefractionated natural product extracts. The mycotoxin methoxycitrinin was isolated from a natural extract and found to selectively activate the CHOP-luciferase reporter at 80 µM. A series of citrinin derivatives was isolated from these extracts, including a unique congener that has not been previously described. In an effort to identify more potent compounds, the authors examined the ability of citrinin and the structurally related mycotoxins ochratoxin A and patulin to activate the UPR. Strikingly, it was found that patulin at 2.5 to 10 µM induced a terminal UPR in a panel of OSCC cells that was characterized by an increase in CHOP, GADD34, and ATF3 gene expression and XBP1 splicing. A luminescent caspase assay and the induction of several BH3-only genes indicated that patulin could induce apoptosis in OSCC cells. These data support the use of this complementary HTS strategy to identify novel modulators of UPR signaling and tumor cell death.

Publisher

Elsevier BV

Cited by 40 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3