Research Article
Radiosensitization by a novel Bcl-2 and Bcl-XL inhibitor S44563 in small-cell lung cancer
Y Loriot, P Mordant, D Dugue, O Geneste, A Gombos, P Opolon, J Guegan, J-L Perfettini, A Pierre, L K Berthier, G Kroemer, J C Soria, S Depil, E Deutsch
Published:
September 01, 2014
DOI:
10.1038/cddis.2014.365
License:
Copyright © 2014 Macmillan Publishers Limited2014Macmillan Publishers LimitedCell Death and Disease is an open-access journal published by Nature Publishing Group. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/3.0/
Abstract
Radiotherapy has a critical role in the treatment of small-cell lung cancer (SCLC). The effectiveness of radiation in SCLC remains limited as resistance results from defects in apoptosis. In the current study, we investigated whether using the Bcl-2/Bcl-XL inhibitor S44563 can enhance radiosensitivity of SCLC cells in vitro and in vivo. In vitro studies confirmed that S44563 caused SCLC cells to acquire hallmarks of apoptosis. S44563 markedly enhanced the sensitivity of SCLC cells to radiation, as determined by a clonogenic assay. The combination of S44563 and cisplatin-based chemo-radiation showed a significant tumor growth delay and increased overall survival in mouse xenograft models. This positive interaction was greater when S44563 was given after the completion of the radiation, which might be explained by the radiation-induced overexpression of anti-apoptotic proteins secondary to activation of the NF-κB pathway. These data underline the possibility of combining IR and Bcl-2/Bcl-XL inhibition in the treatment of SCLC as they underscore the importance of administering conventional and targeted therapies in an optimal sequence.