B. Mukherjee, N. Tomimatsu, K. Amancherla, Cristel V. Camacho, N. Pichamoorthy, S. Burma
{"title":"The dual PI3K/mTOR inhibitor NVP-BEZ235 is a potent inhibitor of ATM- and DNA-PKCs-mediated DNA damage responses.","authors":"B. Mukherjee, N. Tomimatsu, K. Amancherla, Cristel V. Camacho, N. Pichamoorthy, S. Burma","doi":"10.1158/1538-7445.AM2012-3745","DOIUrl":null,"url":null,"abstract":"Inhibitors of PI3K/Akt signaling are being actively developed for tumor therapy owing to the frequent mutational activation of the PI3K-Akt-mTORC1 pathway in many cancers, including glioblastomas (GBMs). NVP-BEZ235 is a novel and potent dual PI3K/mTOR inhibitor that is currently in phase 1/2 clinical trials for advanced solid tumors. Here, we show that NVP-BEZ235 also potently inhibits ATM and DNA-PKcs, the two major kinases responding to ionizing radiation (IR)-induced DNA double-strand breaks (DSBs). Consequently, NVP-BEZ235 blocks both nonhomologous end joining and homologous recombination DNA repair pathways resulting in significant attenuation of DSB repair. In addition, phosphorylation of ATMtargets and implementation of the G(2)/M cell cycle checkpoint are also attenuated by this drug. As a result, NVP-BEZ235 confers an extreme degree of radiosensitization and impairs DSB repair in a panel of GBM cell lines irrespective of their Akt activation status. NVP-BEZ235 also significantly impairs DSB repair in a mouse tumor model thereby validating the efficacy of this drug as a DNA repair inhibitor in vivo. Our results, showing that NVP-BEZ235 is a potent and novel inhibitor of ATM and DNA-PKcs, have important implications for the informed and rational design of clinical trials involving this drug and also reveal the potential utility of NVP-BEZ235 as an effective radiosensitizer for GBMs in the clinic.","PeriodicalId":48716,"journal":{"name":"Neoplasia","volume":null,"pages":null},"PeriodicalIF":6.3000,"publicationDate":"2012-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"169","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Neoplasia","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1158/1538-7445.AM2012-3745","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ONCOLOGY","Score":null,"Total":0}
引用次数: 169
Abstract
Inhibitors of PI3K/Akt signaling are being actively developed for tumor therapy owing to the frequent mutational activation of the PI3K-Akt-mTORC1 pathway in many cancers, including glioblastomas (GBMs). NVP-BEZ235 is a novel and potent dual PI3K/mTOR inhibitor that is currently in phase 1/2 clinical trials for advanced solid tumors. Here, we show that NVP-BEZ235 also potently inhibits ATM and DNA-PKcs, the two major kinases responding to ionizing radiation (IR)-induced DNA double-strand breaks (DSBs). Consequently, NVP-BEZ235 blocks both nonhomologous end joining and homologous recombination DNA repair pathways resulting in significant attenuation of DSB repair. In addition, phosphorylation of ATMtargets and implementation of the G(2)/M cell cycle checkpoint are also attenuated by this drug. As a result, NVP-BEZ235 confers an extreme degree of radiosensitization and impairs DSB repair in a panel of GBM cell lines irrespective of their Akt activation status. NVP-BEZ235 also significantly impairs DSB repair in a mouse tumor model thereby validating the efficacy of this drug as a DNA repair inhibitor in vivo. Our results, showing that NVP-BEZ235 is a potent and novel inhibitor of ATM and DNA-PKcs, have important implications for the informed and rational design of clinical trials involving this drug and also reveal the potential utility of NVP-BEZ235 as an effective radiosensitizer for GBMs in the clinic.
期刊介绍:
Neoplasia publishes the results of novel investigations in all areas of oncology research. The title Neoplasia was chosen to convey the journal’s breadth, which encompasses the traditional disciplines of cancer research as well as emerging fields and interdisciplinary investigations. Neoplasia is interested in studies describing new molecular and genetic findings relating to the neoplastic phenotype and in laboratory and clinical studies demonstrating creative applications of advances in the basic sciences to risk assessment, prognostic indications, detection, diagnosis, and treatment. In addition to regular Research Reports, Neoplasia also publishes Reviews and Meeting Reports. Neoplasia is committed to ensuring a thorough, fair, and rapid review and publication schedule to further its mission of serving both the scientific and clinical communities by disseminating important data and ideas in cancer research.