These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: 17-Allylamino-17-Demethoxygeldanamycin and the Enhancement of PS-341-Induced Lung Cancer Cell Death by Blocking the NF-κB and PI3K/Akt Pathways.
    Author: Lee KH, Jang AH, Yoo CG.
    Journal: Am J Respir Cell Mol Biol; 2015 Sep; 53(3):412-21. PubMed ID: 25633180.
    Abstract:
    PS-341 is a highly selective and potent proteasome inhibitor that is cytotoxic to various types of cancer. However, no objective response was seen in a clinical trial with PS-341 as a single agent in non-small cell lung cancer. Its antitumor activity is limited by the simultaneously activated antiapoptosis pathway. Recently, PS-341-induced NF-κB activation via IκBα degradation has been suggested to be one of its antiapoptotic effects. In this study, we investigated the effects of a combined application of the heat shock protein (Hsp) 90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) with PS-341 in lung cancer cells. Hsp90 inhibition with 17-AAG was effective in enhancing PS-341-induced lung cancer cell death in vitro and in vivo. 17-AAG pretreatment induced the degradation of upstream regulators of IκB, IL-1R-associated kinase-1 (IRAK-1), and IκB kinases (IKKs), dose and time dependently, which resulted in blocking of PS-341-induced IκBα degradation, p65 nuclear translocation, transcriptional activity, and NF-κB-regulated antiapoptotic gene expressions such as COX-2. The concentrations of 17-AAG used for combinatorial treatment with PS-341 did not change cell viability or the activity of proteasome complex. Moreover, 17-AAG pretreatment decreased the level of phsophorylated Akt at serine 473 residue and suppressed active Akt-dependent inactivation of glycogen synthase kinase 3β. 17-AAG mediated the dissociation of its client proteins (IRAK-1, IKKs, and Akt) from the Hsp90 complex. As a result, it induced degradation of target proteins. Our results suggest that the combination of 17-AAG and PS-341 could be an effective anticancer therapy that overcomes the limited effects of PS-341.
    [Abstract] [Full Text] [Related] [New Search]