Tumour microvessel endothelial cell KIT and stem cell factor expression in human solid tumours.
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.
Sihto
Harri
H
Laboratory of Molecular Oncology, Biomedicum Helsinki, Helsinki, Finland. harri.sihto@helsinki.fi
Tynninen
Olli
O
Halonen
Maija
M
Puputti
Marjut
M
Karjalainen-Lindsberg
Marja-Liisa
ML
Kukko
Heli
H
Joensuu
Heikki
H
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*
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019089:Stem Cell Factor