Abstract
Breast cancer cells generally develop resistance to TNF-Related Apoptosis-Inducing Ligand (TRAIL) and, therefore, assistance from sensitizers is required. In our study, we have demonstrated that Spleen tyrosine kinase (Syk) inhibitor Bay 61-3606 was identified as a TRAIL sensitizer. Amplification of TRAIL-induced apoptosis by Bay 61-3606 was accompanied by the strong activation of Bak, caspases, and DNA fragmentation. In mechanism of action, Bay 61-3606 sensitized cells to TRAIL via two mechanisms regulating myeloid cell leukemia sequence-1 (Mcl-1). First, Bay 61-3606 triggered ubiquitin-dependent degradation of Mcl-1 by regulating Mcl-1 phosphorylation. Second, Bay 61-3606 downregulates Mcl-1 expression at the transcription level. In this context, Bay 61-3606 acted as an inhibitor of Cyclin-Dependent Kinase (CDK) 9 rather than Syk. In summary, Bay 61-3606 downregulates Mcl-1 expression in breast cancer cells and sensitizes cancer cells to TRAIL-mediated apoptosis.
Original language | English |
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Article number | e0146073 |
Journal | PLoS ONE |
Volume | 10 |
Issue number | 12 |
DOIs | |
State | Published - 1 Dec 2015 |
Bibliographical note
Publisher Copyright:© 2015 Kim et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.