title: Gauging NOTCH1 Activation in Cancer Using Immunohistochemistry.
abstract: Fixed, paraffin-embedded (FPE) tissues are a potentially rich resource for studying the role of NOTCH1 in cancer and other pathologies, but tests that reliably detect activated NOTCH1 (NICD1) in FPE samples have been lacking. Here, we bridge this gap by developing an immunohistochemical (IHC) stain that detects a neoepitope created by the proteolytic cleavage event that activates NOTCH1. Following validation using xenografted cancers and normal tissues with known patterns of NOTCH1 activation, we applied this test to tumors linked to dysregulated Notch signaling by mutational studies. As expected, frequent NICD1 staining was observed in T lymphoblastic leukemia/lymphoma, a tumor in which activating NOTCH1 mutations are common. However, when IHC was used to gauge NOTCH1 activation in other human cancers, several unexpected findings emerged. Among B cell tumors, NICD1 staining was much more frequent in chronic lymphocytic leukemia than would be predicted based on the frequency of NOTCH1 mutations, while mantle cell lymphoma and diffuse large B cell lymphoma showed no evidence of NOTCH1 activation. NICD1 was also detected in 38% of peripheral T cell lymphomas. Of interest, NICD1 staining in chronic lymphocytic leukemia cells and in angioimmunoblastic lymphoma was consistently more pronounced in lymph nodes than in surrounding soft tissues, implicating factors in the nodal microenvironment in NOTCH1 activation in these diseases. Among carcinomas, diffuse strong NICD1 staining was observed in 3.8% of cases of triple negative breast cancer (3 of 78 tumors), but was absent from 151 non-small cell lung carcinomas and 147 ovarian carcinomas. Frequent staining of normal endothelium was also observed; in line with this observation, strong NICD1 staining was also seen in 77% of angiosarcomas. These findings complement insights from genomic sequencing studies and suggest that IHC staining is a valuable experimental tool that may be useful in selection of patients for clinical trials.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kluk
authors.forename: Todd
authors.initials: T
authors.lastname: Ashworth
authors.forename: Hongfang
authors.initials: H
authors.lastname: Wang
authors.forename: Birgit
authors.initials: B
authors.lastname: Knoechel
authors.forename: Emily F
authors.initials: EF
authors.lastname: Mason
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Morgan
authors.forename: David
authors.initials: D
authors.lastname: Dorfman
authors.forename: Geraldine
authors.initials: G
authors.lastname: Pinkus
authors.forename: Oliver
authors.initials: O
authors.lastname: Weigert
authors.forename: Jason L
authors.initials: JL
authors.lastname: Hornick
authors.forename: Lucian R
authors.initials: LR
authors.lastname: Chirieac
authors.forename: Michelle
authors.initials: M
authors.lastname: Hirsch
authors.forename: David J
authors.initials: DJ
authors.lastname: Oh
authors.forename: Andrew P
authors.initials: AP
authors.lastname: South
authors.forename: Irene M
authors.initials: IM
authors.lastname: Leigh
authors.forename: Celine
authors.initials: C
authors.lastname: Pourreyron
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Cassidy
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Deangelo
authors.forename: David M
authors.initials: DM
authors.lastname: Weinstock
authors.forename: Ian E
authors.initials: IE
authors.lastname: Krop
authors.forename: Deborah
authors.initials: D
authors.lastname: Dillon
authors.forename: Jane E
authors.initials: JE
authors.lastname: Brock
authors.forename: Alexander J F
authors.initials: AJ
authors.lastname: Lazar
authors.forename: Myron
authors.initials: M
authors.lastname: Peto
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Cho
authors.forename: Alexander
authors.initials: A
authors.lastname: Stoeck
authors.forename: Brian B
authors.initials: BB
authors.lastname: Haines
authors.forename: Sriram
authors.initials: S
authors.lastname: Sathayanrayanan
authors.forename: Scott
authors.initials: S
authors.lastname: Rodig
authors.forename: Jon C
authors.initials: JC
authors.lastname: Aster
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D064593:Heterografts; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D009154:Mutation; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*
chemical_list: C497761:NOTCH1 protein, human; D051881:Receptor, Notch1