Open AccessSensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1
Author(s) -
Hak-Bong Kim,
Su-Hoon Lee,
Jee-Hyun Um,
Won Keun Oh,
Dong-Wan Kim,
ChiDug Kang,
SunHee Kim
Publication year - 2015
Publication title -
oncotarget
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.373
H-Index - 127
ISSN - 1949-2553
DOI - 10.18632/oncotarget.5343
Subject(s) - hsp90 inhibitor , hsp90 , multiple drug resistance , hsf1 , heat shock protein , cancer research , cancer cell , hsp27 , hsp70 , cancer , p glycoprotein , leukemia , biology , pharmacology , drug resistance , medicine , immunology , biochemistry , gene , microbiology and biotechnology
The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp.