title: Functional genetics-directed identification of novel pharmacological inhibitors of FAS- and TNF-dependent apoptosis that protect mice from acute liver failure.
abstract: shRNA-mediated gene-silencing technology paired with cell-based functional readouts reveals potential targets directly, providing an opportunity to identify drugs against the target without knowing the precise role of the target in the pathophysiological processes of interest. By screening a lentiviral shRNA library targeting for major components of human signaling pathways and known drug targets, we identified and validated both canonical as well as 52 novel mediators of FAS and TNF ligand-induced apoptosis. Presence of potential therapeutic targets among these mediators was confirmed by demonstration of in vivo activity of siRNAs against four identified target candidates that protected mice from acute liver failure (ALF), a life-threatening disease with known involvement of death receptor (DR)-mediated apoptosis. Network-based modeling was used to predict small-molecule inhibitors for several candidate apoptosis mediators, including somatostatin receptor 5 (SSTR5) and a regulatory subunit of PP2A phosphatase, PPP2R5A. Remarkably, pharmacological inhibition of either SSTR5 or PPP2R5A reduced apoptosis induced by either FASL or TNF in cultured cells and dramatically improved survival in several mouse models of ALF. These results demonstrate the utility of loss-of-function genetic screens and network-based drug-repositioning methods for expedited identification of targeted drug candidates and revealed pharmacological agents potentially suitable for treatment of DR-mediated pathologies.
authors.affiliation: Cellecta, Inc., Mountain View, CA, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Komarov
authors.affiliation: Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Komarova
authors.affiliation: Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: K
authors.initials: K
authors.lastname: Green
authors.affiliation: Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: L R
authors.initials: LR
authors.lastname: Novototskaya
authors.affiliation: Buffalo BioLabs, LLC, Buffalo, NY, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Baker
authors.affiliation: Infectious and Inflammatory Disease Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Eroshkin
authors.affiliation: Buffalo BioLabs, LLC, Buffalo, NY, USA.|Infectious and Inflammatory Disease Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Osterman
authors.affiliation: Cellecta, Inc., Mountain View, CA, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Chenchick
authors.affiliation: Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: C
authors.initials: C
authors.lastname: Frangou
authors.affiliation: Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: A V
authors.initials: AV
authors.lastname: Gudkov
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D055808:Drug Discovery; D005260:Female; D006367:HeLa Cells; D006801:Humans; D017114:Liver Failure, Acute / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: C491901:FAS protein, human; C491899:Fas protein, mouse; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor