title: Identification of an allosteric small-molecule inhibitor selective for the inducible form of heat shock protein 70.
abstract: Inducible Hsp70 (Hsp70i) is overexpressed in a wide spectrum of human tumors, and its expression correlates with metastasis, poor outcomes, and resistance to chemotherapy in patients. Identification of small-molecule inhibitors selective for Hsp70i could provide new therapeutic tools for cancer treatment. In this work, we used fluorescence-linked enzyme chemoproteomic strategy (FLECS) to identify HS-72, an allosteric inhibitor selective for Hsp70i. HS-72 displays the hallmarks of Hsp70 inhibition in cells, promoting substrate protein degradation and growth inhibition. Importantly, HS-72 is selective for Hsp70i over the closely related constitutively active Hsc70. Studies with purified protein show HS-72 acts as an allosteric inhibitor, reducing ATP affinity. In vivo HS-72 is well-tolerated, showing bioavailability and efficacy, inhibiting tumor growth and promoting survival in a HER2+ model of breast cancer. The HS-72 scaffold is amenable to resynthesis and iteration, suggesting an ideal starting point for a new generation of anticancer therapeutics targeting Hsp70i.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Howe
authors.affiliation: Department of Applied Biology, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan.
authors.forename: Khaldon
authors.initials: K
authors.lastname: Bodoor
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Carlson
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Philip F
authors.initials: PF
authors.lastname: Hughes
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Yazan
authors.initials: Y
authors.lastname: Alwarawrah
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Loiselle
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Jaeger
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Darr
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Jordan
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Lucas M
authors.initials: LM
authors.lastname: Hunter
authors.affiliation: Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Eileen T
authors.initials: ET
authors.lastname: Molzberger
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors.forename: Theodore A
authors.initials: TA
authors.lastname: Gobillot
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA; Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Thiele
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Brodsky
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Neil L
authors.initials: NL
authors.lastname: Spector
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA. Electronic address: timothy.haystead@dm.duke.edu.
authors.forename: Timothy A J
authors.initials: TA
authors.lastname: Haystead
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects; D000818:Animals; D001562:Benzimidazoles / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D001682:Biological Availability; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D004789:Enzyme Activation / Q000187:drug effects; D057809:HEK293 Cells; D018840:HSP70 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D009557:Nipecotic Acids / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D010539:Permeability; D010880:Piperidines / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D066329:Protein Aggregates / Q000187:drug effects; D017434:Protein Structure, Tertiary; D023041:Xenograft Model Antitumor Assays
chemical_list: D001562:Benzimidazoles; C000600301:HS-72 compound; D018840:HSP70 Heat-Shock Proteins; D009557:Nipecotic Acids; D010880:Piperidines; D066329:Protein Aggregates; D020169:Caspases