title: DOG1 for the diagnosis of gastrointestinal stromal tumor (GIST): Comparison between 2 different antibodies.
abstract: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Discovered on GIST-1 (DOG1) is a recently described protein expressed in GISTs irrespective of mutation status. The aim of this study was to investigate the immunohistochemical expression of DOG1 using 2 different monoclonal antibodies (DOG1.1 and the commercially available K9 antibody) in 668 GIST cases and to compare the results with the expression of KIT. DOG1 and KIT expression also were studied in most human normal tissues and several nonmesenchymal and mesenchymal tumors other than GIST. KIT was expressed in 643 (96.3%) GISTs. DOG1.1 and K9 were positive in 538 (80.5%) and 642 (96.1%) GIST cases, respectively. In 25 (3.7%) KIT-negative GIST cases, DOG1 was expressed in 5 (20.0%) and 19 (76.0%) using DOG1.1 and K9 antibodies, respectively. Only 0.9% of GISTs were negative for KIT, DOG1.1, and K9. Most normal human tissues did not reveal KIT and DOG1 expression. DOG1.1 was positive in only 2 of 57 synovial sarcomas and 1 of 61 soft tissue leiomyosarcomas. K9 was positive in 5 of 57 synovial sarcomas, 1 of 14 angiosarcomas, 1 of 61 soft tissue leiomyosarcomas, 3 of 4 adenoid cystic carcinomas of the head and neck, and in myoepithelial cells of 9 of 11 fibroadenomas of the breast. In conclusion, the commercially available K9 is of great utility for the diagnosis of most KIT-negative GISTs, and the combination of both KIT and K9 antibody in a panel of immunohistochemistry can define the diagnosis of GIST in more than 99% of cases.
authors.affiliation: University of São Paulo, SP, Brazil.
authors.forename: Lisandro F
authors.initials: LF
authors.lastname: Lopes
authors.forename: Robert B
authors.initials: RB
authors.lastname: West
authors.forename: Livia M
authors.initials: LM
authors.lastname: Bacchi
authors.forename: Matt
authors.initials: M
authors.lastname: van de Rijn
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Bacchi
mesh_terms: D000075369:Anoctamin-1; D000911:Antibodies, Monoclonal; D018118:Chloride Channels; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D046228:Microarray Analysis; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit; D012509:Sarcoma / Q000175:diagnosis*
chemical_list: C476213:ANO1 protein, human; D000075369:Anoctamin-1; D000911:Antibodies, Monoclonal; D018118:Chloride Channels; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019009:Proto-Oncogene Proteins c-kit