title: Differential expression of the c-kit proto-oncogene in germ cell tumours.
abstract: The c-kit proto-oncogene product and its ligand stem cell factor play an important role in haematopoiesis, spermatogenesis, and melanogenesis. Using an anti-c-kit antiserum raised against a synthetic peptide, we studied the immunohistochemical expression of the c-kit gene product in 60 germ cell tumours (GCTs) (53 testicular, 7 extragonadal), derived from primary GCTs in 45 cases and metastatic tumours in 15 cases. Twenty-eight out of 28 seminomas showed c-kit membranous staining in the majority of cells. A similar pattern of expression was seen in intratubular germ cell neoplasia. Nine out of 29 (32 per cent) non-seminomas displayed cytoplasmic, but not membranous, c-kit immunoreactivity in occasional cells. In three mixed GCTs, c-kit expression was limited to the seminoma component. In normal testis, c-kit expression was observed in some basal tubular cells, corresponding to undifferentiated spermatogonia. These results suggest a role for c-kit in the oncogenesis of GCT, where down-regulation of c-kit might be a critical step during progression from seminomas to non-seminomas. Immunohistochemical analysis of c-kit should be considered as a diagnostic aid for GCT and in particular may be helpful in the identification of certain extragonadal seminomas.
authors.affiliation: Department of Pathology, Free University Hospital, Amsterdam, The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Izquierdo
authors.forename: P
authors.initials: P
authors.lastname: Van der Valk
authors.forename: J
authors.initials: J
authors.lastname: Van Ark-Otte
authors.forename: G
authors.initials: G
authors.lastname: Rubio
authors.forename: J R
authors.initials: JR
authors.lastname: Germa-Lluch
authors.forename: R
authors.initials: R
authors.lastname: Ueda
authors.forename: R J
authors.initials: RJ
authors.lastname: Scheper
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: G
authors.initials: G
authors.lastname: Giaccone
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005260:Female; D015870:Gene Expression; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism*; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D018239:Seminoma / Q000378:metabolism; D013736:Testicular Neoplasms / Q000378:metabolism*; D013737:Testis / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C000715470:MAS1 protein, human; D009363:Neoplasm Proteins; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit