title: Tumour microvessel endothelial cell KIT and stem cell factor expression in human solid tumours.
abstract: OBJECTIVE
  To assess KIT receptor tyrosine kinase and stem cell factor (SCF, KIT ligand) expression in tumour microvessel endothelial cells.
  
  
  RESULTS
  KIT and SCF expression were studied in 248 human tumours consisting of 15 different histological types using immunohistochemistry and in situ hybridization for KIT messenger RNA. Moderate to strong intratumoral endothelial cell KIT expression was present in 11 of the 15 tumour types, and was most common in glioblastoma (58%), mixed embryonal carcinoma with teratoma (33%) and renal clear cell carcinoma (29%). Results of in situ hybridization were in line with those obtained with immunohistochemistry in the cases studied (n = 9). Marked SCF expression was uncommon in tumour endothelial cells, but frequent in perinecrotic tumour cells. Patients with glioblastoma with moderate to strong endothelial cell KIT expression had more favourable survival than those whose tumour showed little or no expression (P = 0.024). Glioblastoma patients whose tumour expressed SCF had an unfavourable outcome compared with those with tumour with weak or no expression (P = 0.034).
  
  
  CONCLUSIONS
  Intratumoral microvessels of several types of human malignant tumours express KIT. Tumour cell SCF expression and absence of marked endothelial cell KIT expression are novel adverse prognostic features in glioblastoma.
authors.affiliation: Laboratory of Molecular Oncology, Biomedicum Helsinki, Helsinki, Finland. harri.sihto@helsinki.fi
authors.forename: Harri
authors.initials: H
authors.lastname: Sihto
authors.forename: Olli
authors.initials: O
authors.lastname: Tynninen
authors.forename: Maija
authors.initials: M
authors.lastname: Halonen
authors.forename: Marjut
authors.initials: M
authors.lastname: Puputti
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Karjalainen-Lindsberg
authors.forename: Heli
authors.initials: H
authors.lastname: Kukko
authors.forename: Heikki
authors.initials: H
authors.lastname: Joensuu
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001932:Brain Neoplasms / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D005909:Glioblastoma / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008297:Male; D055806:Microvessels / Q000378:metabolism; D009369:Neoplasms / Q000098:blood supply / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis; D019089:Stem Cell Factor / Q000096:biosynthesis*
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019089:Stem Cell Factor