Role of Acetylation and Extracellular Location of Heat Shock Protein 90α in Tumor Cell Invasion

Yang, Yaping; Rao, Raghunatha N.; Shen, Jie; Tang, Yun; Fiskus, Warren; Nechtman, John; Atadja, Peter; Bhalla, Kapil N.

doi:10.1158/0008-5472.can-08-0644

Cited by 207 publications

(253 citation statements)

References 47 publications

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“…4A). Although human Hsp90 is also reported to be acetylated (22), the sites of acetylation do not coincide with those for PfHsp90 found in this study. Interestingly, the interaction site of Hsp90 with co-chaperones p23 and Aha1, as reported in yeast, was found to coincide with Lys-426 of PfHsp90 (supplemental Fig.…”

Section: Pfhsp90 Is Hypersensitive To Ga-mediated Inhibition Of Itscontrasting

confidence: 93%

Heat Shock Protein 90 as a Drug Target against Protozoan Infections

Pallavi

Roy

Nageshan

et al. 2010

Journal of Biological Chemistry

149

141

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Using a pharmacological inhibitor of Hsp90 in cultured malarial parasite, we have previously implicated Plasmodium falciparum Hsp90 (PfHsp90) as a drug target against malaria. In this study, we have biochemically characterized PfHsp90 in terms of its ATPase activity and interaction with its inhibitor geldanamycin (GA) and evaluated its potential as a drug target in a preclinical mouse model of malaria. In addition, we have explored the potential of Hsp90 inhibitors as drugs for the treatment of Trypanosoma infection in animals. Our studies with full-length PfHsp90 showed it to have the highest ATPase activity of all known Hsp90s; its ATPase activity was 6 times higher than that of human Hsp90. Also, GA brought about more robust inhibition of PfHsp90 ATPase activity as compared with human Hsp90. Mass spectrometric analysis of PfHsp90 expressed in P. falciparum identified a site of acetylation that overlapped with Aha1 and p23 binding domain, suggesting its role in modulating Hsp90 multichaperone complex assembly. Indeed, treatment of P. falciparum cultures with a histone deacetylase inhibitor resulted in a partial dissociation of PfHsp90 complex. Furthermore, we found a well known, semisynthetic Hsp90 inhibitor, namely 17-(allylamino)-17-demethoxygeldanamycin, to be effective in attenuating parasite growth and prolonging survival in a mouse model of malaria. We also characterized GA binding to Hsp90 from another protozoan parasite, namely Trypanosoma evansi. We found 17-(allylamino)-17-demethoxygeldanamycin to potently inhibit T. evansi growth in a mouse model of trypanosomiasis. In all, our biochemical characterization, drug interaction, and animal studies supported Hsp90 as a drug target and its inhibitor as a potential drug against protozoan diseases.

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Section: Pfhsp90 Is Hypersensitive To Ga-mediated Inhibition Of Itscontrasting

confidence: 93%

Heat Shock Protein 90 as a Drug Target against Protozoan Infections

Pallavi

Roy

Nageshan

et al. 2010

Journal of Biological Chemistry

149

141

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“…Furthermore, the binding affinities of Hsp90 for inhibitors can be influenced by its interactions with co-chaperones [17,22,[37][38][39][40][41], which in turn may be modulated by posttranslational modifications of Hsp90 (see for example refs. [42][43][44]). Since we had found that the Hsp90 co-chaperone p23 directly protects Hsp90 from binding inhibitors [22], we did introduce the Pf p23 ortholog into yeast.…”

Section: Discussionmentioning

confidence: 99%

The complementation of yeast with human or Plasmodium falciparum Hsp90 confers differential inhibitor sensitivities

Wider

Péli-Gulli

Briand

et al. 2009

Molecular and Biochemical Parasitology

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Developing novel drugs against the unicellular parasite Plasmodium is complicated by the paucity of simple screening systems. Heat-shock proteins are an essential class of proteins for the parasite's cyclical life style between different cellular milieus and temperatures. The molecular chaperone Hsp90 assists a large variety of proteins, but its supporting functions for many proteins that are important for cancer have made it into a well-studied drug target. With a better understanding of the differences between Hsp90 of the malarial parasite and Hsp90 of its human host, new therapeutic options might become available. We have generated a set of isogenic strains of the budding yeast Saccharomyces cerevisiae where the essential yeast Hsp90 proteins have been replaced with either of the two human cytosolic isoforms Hsp90α or Hsp90β, or with Hsp90 from Plasmodium falciparum (Pf). All strains express large amounts of the Flag-tagged Hsp90 proteins and are viable. Even though the strain with Pf Hsp90 grows more poorly, it provides a tool to reconstitute additional aspects of the parasite Hsp90 complex and its interactions with substrates in yeast as a living test tube. Upon exposure of the set of Hsp90 test strains to the two Hsp90 inhibitors radicicol (Rd) and geldanamycin (GA), we found that the strain with Pf Hsp90 is relatively more sensitive to GA than to Rd compared to the strains with human Hsp90's. This indicates that this set of yeast strains could be used to screen for new Pf Hsp90 inhibitors with a wider therapeutic window

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“…It is also a key co-chaperone of Hsp90 that is involved in the maturation, stabilization, activation and function of oncogenic proteins [12] . Thus, disrupting the AHA1/Hsp90 complex would cause the depletion of client proteins and kinase clients that are involved in tumor cell proliferation and survival, as well as in all the hallmark traits of malignancy.…”

Section: Original Articlementioning

confidence: 99%

“…The protein concentration in the cell lysates was quantified using the Quick Start Bradford Dye Reagent (Bio-Rad), and the samples were subjected to SDS-PAGE. Western blot analysis was performed as described previously [12] . β-Actin was used as a loading control.…”

Section: Chemicalsmentioning

confidence: 99%

“…Cellular extracts were prepared by directly adding lysis buffer to the cells on ice. For the immunoprecipitation (IP) assays, the cellular extracts were prepared, and IP was performed as described previously [12] . For immunoblotting, cellular extracts or immunoprecipitates were separated by SDS-PAGE, transferred to a nitrocellulose membrane, probed with antibodies, and visualized with enhanced chemiluminescence, as described previously [12] .…”

Section: Transfections Immunoprecipitation Assays and Immunoblotsmentioning

confidence: 99%

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The flavonoid TL-2-8 induces cell death and immature mitophagy in breast cancer cells via abrogating the function of the AHA1/Hsp90 complex

et al. 2017

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The flavonoid quercetin exhibits significant anticancer activities with few side effects. In the current study, we characterized TL-2-8, a quercetin derivative, as a novel anticancer agent in vitro and in vivo. Cell proliferation and viability were assessed using Cell Counting Kit-8 and CellTiter-Blue assay, respectively. Cell death was examined using PI staining or a TUNEL assay. Mitophagy was determined by measuring autophagic flux and by confocal imaging. Protein expression was examined by Western blotting. We found that TL-2-8 selectively inhibited the proliferation and decreased the viability of various cancer cells (the anti-proliferation IC 50 values in MDA-MB-231, MDA-MB-468 and MCF-7 breast cancer cells at 72 h were 8.28, 8.56, and 9.58 μmol/L, respectively), and it displayed only slight cytotoxicity against normal MCF-10A and HEK-293 cells. In MDA-MB-231 and MDA-MB-468 breast cancer cells, TL-2-8 treatment induced the degradation of multiple Hsp90 client proteins without inducing Hsp70. TL-2-8 (3, 6, 12 μmol/L) dose-dependently inhibited the expression of AHA1, an activator of Hsp90 ATPase, and decreased Hsp90-AHA1 complex formation, leading to decreased Hsp90 chaperone function and reduced polo-like kinase 1 (PLK1) signaling. Consequently, impaired mitophagy was induced via the downregulation of lysosomal-associated membrane protein 2 (LAMP2). The in vivo anticancer effects of TL-2-8 were evaluated in an MDA-MB-231 breast cancer xenograft model, which was treated with TL-2-8 (25, 50, 100 mg·kg -1 ·d -1 , po). Administration of TL-2-8 resulted in tumor growth inhibition rates of 37.9%, 58.9% and 70.9%, respectively, whereas quercetin treatment (100 mg·kg -1 ·d -1 , po) produced only a lower tumor growth inhibition rate (49.5%). Furthermore, TL-2-8 treatment significantly extended the lifespan of mice bearing MDA-MB-231 breast cancer cell xenografts. Our results demonstrate that TL-2-8 induces significant cell death and immature mitophagy in breast cancer cells in vitro and in vivo via AHA1 abrogation.

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Role of Acetylation and Extracellular Location of Heat Shock Protein 90α in Tumor Cell Invasion

Cited by 207 publications

References 47 publications

Heat Shock Protein 90 as a Drug Target against Protozoan Infections

Heat Shock Protein 90 as a Drug Target against Protozoan Infections

The complementation of yeast with human or Plasmodium falciparum Hsp90 confers differential inhibitor sensitivities

The flavonoid TL-2-8 induces cell death and immature mitophagy in breast cancer cells via abrogating the function of the AHA1/Hsp90 complex

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