A TrxR inhibiting gold(I) NHC complex induces apoptosis through ASK1-p38-MAPK signaling in pancreatic cancer cells

Molecular Cancer

Research

Suzan Can¹  Palvo Holenya¹  Xinlai Cheng¹  Stefan Wölfl¹  Hamed Alborzinia¹  Riccardo Rubbiani²  Ingo Ott² 

[1] Institut für Pharmazie und Molekulare Biotechnologie, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 364, 69120, Heidelberg, Germany;Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstrasse 55, 38106, Braunschweig, Germany;

关键词: Gold(I) NHC complex;    Apoptosis;    Thiolredoxin Reductase inhibitor;    ASK1;    p38-MAPK;    Anti-cancer drug;    ROS;    PDAC;   

DOI  :  10.1186/1476-4598-13-221

 received in 2014-03-20, accepted in 2014-09-04,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundCancer cells in the advanced stage show aberrant antioxidant capacity to detoxify excessive ROS resulting in the compensation for intrinsic oxidative stress and therapeutic resistance. PDAC is one of the most lethal cancers and often associated with a high accumulation of ROS. Recent studies identified gold(I) NHC complexes as potent TrxR inhibitors suppressing cell growth in a wide spectrum of human malignant cell lines at the low micromolar concentration. However, the mechanism of action is not completely elucidated yet.MethodsTo understand the biological function of gold(I) NHC complexes in PDAC, we used a recently published gold(I) NHC complex, MC3, and evaluated its anti-proliferative effect in four PDAC cell lines, determined by MTT and SRB assays. In further detailed analysis, we analyzed cellular ROS levels using the ROS indicator DHE and mitochondrial membrane potential indicated by the dye JC-1 in Panc1. We also analyzed cell cycle arrest and apoptosis by FACS. To elucidate the role of specific cell signaling pathways in MC3-induced cell death, co-incubation with ROS scavengers, a p38-MAPK inhibitor and siRNA mediated depletion of ASK1 were performed, and results were analyzed by immunoblotting, ELISA-microarrays, qRT-PCR and immunoprecipitation.ResultsOur data demonstrate that MC3 efficiently suppressed cell growth, and induced cell cycle arrest and apoptosis in pancreatic cancer cells, in particular in the gemcitabine-resistant cancer cells Panc1 and ASPC1. Treatment with MC3 resulted in a substantial alteration of the cellular redox homeostasis leading to increased ROS levels and a decrease in the mitochondrial membrane potential. ROS scavengers suppressed ROS formation and rescued cells from damage. On the molecular level, MC3 blocked the interaction of Trx with ASK1 and subsequently activated p38-associated signaling. Furthermore, inhibition of this pathway by using ASK1 siRNA or a p38 inhibitor clearly attenuated the effect of MC3 on cell proliferation in Panc1 and ASPC1.ConclusionsOur results confirm that MC3 is a TrxR inhibitor and show MC3 induced apoptosis in gemcitabine-resistant PDACs. MC3 mediated cell death could be blocked by using anti-oxidants, ASK1 siRNA or p38 inhibitor suggesting that the Trx-ASK1-p38 signal cascade played an important role in gold(I) NHC complexes-mediated cellular damage.

【 授权许可】

Unknown   
© Cheng et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.