title: A small molecule inhibitor of the Wnt antagonist secreted frizzled-related protein-1 stimulates bone formation.
abstract: Canonical Wnt signaling has been demonstrated to increase bone formation, and Wnt pathway components are being pursued as potential drug targets for osteoporosis and other metabolic bone diseases. Deletion of the Wnt antagonist secreted frizzled-related protein (sFRP)-1 in mice activates canonical signaling in bone and increases trabecular bone formation in aged animals. We have developed small molecules that bind to and inhibit sFRP-1 in vitro and demonstrate robust anabolic activity in an ex vivo organ culture assay. A library of over 440,000 drug-like compounds was screened for inhibitors of human sFRP-1 using a cell-based functional assay that measured activation of canonical Wnt signaling with an optimized T-cell factor (TCF)-luciferase reporter gene assay. One of the hits in this screen, a diarylsulfone sulfonamide, bound to sFRP-1 with a K(D) of 0.35 microM in a tryptophan fluorescence quenching assay. This compound also selectively inhibited sFRP-1 with an EC(50) of 3.9 microM in the cell-based functional assay. Optimization of this high throughput screening hit for binding and functional potency as well as metabolic stability and other pharmaceutical properties led to improved lead compounds. One of these leads (WAY-316606) bound to sFRP-1 with a K(D) of 0.08 microM and inhibited it with an EC(50) of 0.65 microM. Moreover, this compound increased total bone area in a murine calvarial organ culture assay at concentrations as low as 0.0001 microM. This work demonstrates the feasibility of developing small molecules that inhibit sFRP-1 and stimulate canonical Wnt signaling to increase bone formation.
authors.affiliation: Women's Health and Musculoskeletal Biology, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA. bodinep@wyeth.com
authors.forename: Peter V N
authors.initials: PV
authors.lastname: Bodine
authors.forename: Barbara
authors.initials: B
authors.lastname: Stauffer
authors.forename: Helga
authors.initials: H
authors.lastname: Ponce-de-Leon
authors.forename: Ramesh A
authors.initials: RA
authors.lastname: Bhat
authors.forename: Annamarie
authors.initials: A
authors.lastname: Mangine
authors.forename: Laura M
authors.initials: LM
authors.lastname: Seestaller-Wehr
authors.forename: Robert A
authors.initials: RA
authors.lastname: Moran
authors.forename: Julia
authors.initials: J
authors.lastname: Billiard
authors.forename: Shoichi
authors.initials: S
authors.lastname: Fukayama
authors.forename: Barry S
authors.initials: BS
authors.lastname: Komm
authors.forename: Keith
authors.initials: K
authors.lastname: Pitts
authors.forename: Girija
authors.initials: G
authors.lastname: Krishnamurthy
authors.forename: Ariamala
authors.initials: A
authors.lastname: Gopalsamy
authors.forename: Mengxiao
authors.initials: M
authors.lastname: Shi
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Kern
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Commons
authors.forename: Richard P
authors.initials: RP
authors.lastname: Woodworth
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Wilson
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Welmaker
authors.forename: Eugene J
authors.initials: EJ
authors.lastname: Trybulski
authors.forename: William J
authors.initials: WJ
authors.lastname: Moore
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D010011:Osteocytes / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects*; D011506:Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D012886:Skull / Q000166:cytology / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013449:Sulfonamides / Q000737:chemistry / Q000494:pharmacology*; D051153:Wnt Proteins / Q000037:antagonists & inhibitors*; D000099274:Frizzled-Related Proteins
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D013449:Sulfonamides; D051153:Wnt Proteins; D000099274:Frizzled-Related Proteins