Synergistic Anticancer Activity of Arsenic Trioxide with Erlotinib Is Based on Inhibition of EGFR-Mediated DNA Double-Strand Break Repair

Author(s)
Kushtrim Kryeziu, Ute Jungwirth, Mir Alireza Hoda, Franziska Ferk, Claudia Karnthaler-Benbakka, Siegfried Knasmüller, Christian Kowol, Walter Berger, Petra Heffeter
Abstract

Arsenic trioxide (ATO), one of the oldest remedies used in traditional medicine, was recently rediscovered as an anticancer drug and approved for treatment of relapsed acute promyelocytic leukemia. However, its activity against nonhematologic cancers is rather limited so far. Here, we show that inhibition of ATO-mediated EGF receptor (EGFR) activation can be used to potently sensitize diverse solid cancer types against ATO. Thus, combination of ATO and the EGFR inhibitor erlotinib exerted synergistic activity against multiple cancer cell lines. Subsequent analyses revealed that this effect was based on the blockade of ATO-induced EGFR phosphorylation leading to more pronounced G(2)-M arrest as well as enhanced and more rapid induction of apoptosis. Comparable ATO-sensitizing effects were also found with PI3K/AKT and mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitors, suggesting an essential role of the EGFR-mediated downstream signaling pathway in cancer cell protection against ATO. H2AX staining and comet assay revealed that erlotinib significantly increases ATO-induced DNA double-strand breaks (DSB) well in accordance with a role of the EGFR signaling axis in DNA damage repair. Indeed, EGFR inhibition led to downregulation of several DNA DSB repair proteins such as Rad51 and Rad50 as well as reduced phosphorylation of BRCA1. Finally, the combination treatment of ATO and erlotinib was also distinctly superior to both monotreatments against the notoriously therapy-resistant human A549 lung cancer and the orthotopic p31 mesothelioma xenograft model in vivo. In conclusion, this study suggests that combination of ATO and EGFR inhibitors is a promising therapeutic strategy against various solid tumors harboring wild-type EGFR.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
Medizinische Universität Wien
Journal
Molecular Cancer Therapeutics
Volume
12
Pages
1073-1084
No. of pages
12
ISSN
1535-7163
DOI
https://doi.org/10.1158/1535-7163.MCT-13-0065
Publication date
2013
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry, 106002 Biochemistry, 302055 Oncology
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/7927a16d-6259-4392-bab4-478e10753d0a