Abstract
Recent studies have shown that many types of cancer cells have increased levels of reactive oxygen species (ROS) and enhance antioxidant capacity as an adaptation to intrinsic oxidative stress, suggesting that cancer cells are more vulnerable to oxidative insults and are more dependent on antioxidant systems compared with normal cells. Thus, disruption of redox homeostasis caused by a decline in antioxidant capacity may provide a method for the selective death of cancer cells. Here we show that ROS-mediated selective death of tumor cells can be caused by inhibiting sulfiredoxin (Srx), which reduces hyperoxidized peroxiredoxins, leading to their reactivation. Srx inhibitor increased the accumulation of sulfinic peroxiredoxins and ROS, which led to oxidative mitochondrial damage and caspase activation, resulting in the death of A549 human lung adenocarcinoma cells. Srx depletion also inhibited the growth of A549 cells like Srx inhibition, and the cytotoxic effects of Srx inhibitor were considerably reversed by Srx overexpression or antioxidants such as N-acetyl cysteine and butylated hydroxyanisol. Moreover, Srx inhibitor rendered tumorigenic ovarian cells more susceptible to ROS-mediated death compared with nontumorigenic cells and significantly suppressed the growth of A549 xenografts without acute toxicity. Our results suggest that Srx might serve as a novel therapeutic target for cancer treatment based on ROS-mediated cell death.
Original language | English |
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Pages (from-to) | 264-274 |
Number of pages | 11 |
Journal | Free Radical Biology and Medicine |
Volume | 91 |
DOIs | |
State | Published - 1 Feb 2016 |
Bibliographical note
Funding Information:We would like to acknowledge the University of Texas MD Anderson Cancer Center (UTMDACC), which provided the T80 and T80H cell lines. This work was supported by Grants from the National Research Foundation (NRF) ( 2014R1A2A2A01003983 , 2012R1A5A1048236 , 2012M3A9C5048708 , 2010-0014648 and M10642040002-07N4204-00210 ), funded by the Korean Ministry of Science, ICT and Future Planning (MSIP) , and the Brain Korea 21 Program (to J. Kim), funded by the Korean Ministry of Education .
Funding Information:
We would like to acknowledge the University of Texas MD Anderson Cancer Center (UTMDACC), which provided the T80 and T80H cell lines. This work was supported by Grants from the National Research Foundation (NRF)2014R1A2A2A01003983, 2012R1A5A1048236, 2012M3A9C5048708 and), funded by the Korean Ministry of Science, ICT and Future Planning (MSIP), and the Brain Korea 21 Program (to J. Kim), funded by the Korean Ministry of Education.
Publisher Copyright:
© 2015 Elsevier Inc. All rights reserved.
Keywords
- Apoptosis
- Cancer
- Mitochondrial damage
- Reactiveoxygenspecies
- Sulfiredoxin