Targeting the Hsp90-associated viral oncoproteome in gammaherpesvirus-associated malignancies Journal Article

Authors: Nayar, U.; Lu, P.; Goldstein, R. L.; Vider, J.; Ballon, G.; Rodina, A.; Taldone, T.; Erdjument-Bromage, H.; Chomet, M.; Blasberg, R.; Melnick, A.; Cerchietti, L.; Chiosis, G.; Wang, Y. L.; Cesarman, E.
Article Title: Targeting the Hsp90-associated viral oncoproteome in gammaherpesvirus-associated malignancies
Abstract: PU-H71 is a purine-scaffold Hsp90 inhibitor that, in contrast to other Hsp90 inhibitors, displays unique selectivity for binding the fraction of Hsp90 that is preferentially associated with oncogenic client proteins and enriched in tumor cells (teHsp90). This property allows PU-H71 to potently suppress teHsp90 without inducing toxicity in normal cells. We found that lymphoma cells infected by Epstein-Barr virus or Kaposi sarcoma-associated herpes virus (KSHV) are exquisitely sensitive to this compound. Using PU-H71 affinity capture and proteomics, an unbiased approach to reveal oncogenic networks, we identified the teHsp90 interactome in KSHV+ primary effusion lymphoma cells. Viral and cellular proteins were identified, including many involved in nuclear factor (NF)-kappa B signaling, apoptosis, and autophagy. KSHV vFLIP is a viral oncoprotein homologous to cFLIPs, with NF-kappa B-activating and antiapoptotic activities. We show that teHsp90 binds vFLIP but not cFLIPs. Treatment with PU-H71 induced degradation of vFLIP and IKK gamma, NF-kappa B downregulation, apoptosis and autophagy in vitro, and more importantly, tumor responses in mice. Analysis of the interactome revealed apoptosis as a central pathway; therefore, we tested a BCL2 family inhibitor in primary effusion lymphoma cells. We found strong activity and synergy with PU-H71. Our findings demonstrate PU-H71 affinity capture identifies actionable networks that may help design rational combinations of effective therapies.
Keywords: in-vivo; gene-expression; nf-kappa-b; endothelial-cells; kaposis-sarcoma; sarcoma-associated herpesvirus; dna-sequences; effusion; shock-protein 90; hsp90 inhibitors; lymphoma-cells
Journal Title: Blood
Volume: 122
Issue: 16
ISSN: 0006-4971
Publisher: American Society of Hematology  
Date Published: 2013-10-17
Start Page: 2837
End Page: 2847
Language: English
ACCESSION: WOS:000326080200016
DOI: 10.1182/blood-2013-01-479972
PMCID: PMC3798998
PUBMED: 23943653
Notes: Article -- Source: Wos
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