title: Modulation of Notch signaling by antibodies specific for the extracellular negative regulatory region of NOTCH3.
abstract: The Notch pathway regulates the development of many tissues and cell types and is involved in a variety of human diseases, making it an attractive potential therapeutic target. This promise has been limited by the absence of potent inhibitors or agonists that are specific for individual human Notch receptors (NOTCH1-4). Using an unbiased functional screening, we identified monoclonal antibodies that specifically inhibit or induce activating proteolytic cleavages in NOTCH3. Remarkably, the most potent inhibitory and activating antibodies bind to overlapping epitopes within a juxtamembrane negative regulatory region that protects NOTCH3 from proteolysis and activation in its resting autoinhibited state. The inhibitory antibodies revert phenotypes conveyed on 293T cells by NOTCH3 signaling, such as increased cellular proliferation, survival, and motility, whereas the activating antibody mimics some of the effects of ligand-induced Notch activation. These findings provide insights into the mechanisms of Notch autoinhibition and activation and pave the way for the further development of specific antibody-based modulators of the Notch receptors, which are likely to be of utility in a wide range of experimental and therapeutic settings.
authors.affiliation: Tanox, Incorporated, Houston, Texas 77025, USA. kyfli@yahoo.com
authors.forename: Kang
authors.initials: K
authors.lastname: Li
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Li
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Wu
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Gordon
authors.forename: David W
authors.initials: DW
authors.lastname: Chang
authors.forename: Mason
authors.initials: M
authors.lastname: Lu
authors.forename: Shane
authors.initials: S
authors.lastname: Scoggin
authors.forename: Tihui
authors.initials: T
authors.lastname: Fu
authors.forename: Long
authors.initials: L
authors.lastname: Vien
authors.forename: Gavin
authors.initials: G
authors.lastname: Histen
authors.forename: Ji
authors.initials: J
authors.lastname: Zheng
authors.forename: Rachel
authors.initials: R
authors.lastname: Martin-Hollister
authors.forename: Thomas
authors.initials: T
authors.lastname: Duensing
authors.forename: Sanjaya
authors.initials: S
authors.lastname: Singh
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Blacklow
authors.forename: Zhengbin
authors.initials: Z
authors.lastname: Yao
authors.forename: Jon C
authors.initials: JC
authors.lastname: Aster
authors.forename: Bin-Bing S
authors.initials: BB
authors.lastname: Zhou
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D000918:Antibody Specificity / Q000276:immunology; D002465:Cell Movement / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D000939:Epitopes / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D006801:Humans; D000071656:Receptor, Notch3; D051880:Receptors, Notch / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; C499374:NOTCH3 protein, human; D000071656:Receptor, Notch3; D051880:Receptors, Notch