T. Strohmeyer et al., EXPRESSION OF THE C-KIT PROTOONCOGENE AND ITS LIGAND STEM-CELL FACTOR(SCF) IN NORMAL AND MALIGNANT HUMAN TESTICULAR TISSUE, The Journal of urology, 153(2), 1995, pp. 511-515
Recent findings suggest an important role of the proto-oncogene c-kit,
a surface membrane receptor of the tyrosine kinase family, and its li
gand stem cell factor (SCF) in normal spermatogenesis and possibly in
the pathogenesis of certain testicular germ cell tumors. To further in
vestigate this potential role, the expression of c-kit and SCF was stu
died in normal and malignant human testicular tissue specimens at the
mRNA and protein level by Northern blot analysis and immunohistochemis
try, respectively. The detection of the c-kit receptor in normal human
germ cells and its natural ligand SCF in Sertoli cells suggests the p
resence of a local trophic regulatory system that may be active in hum
an spermatogenesis. Additionally, c-kit expression was detected in the
seminoma but not in the nonseminoma subtype of human testicular germ
cell tumors (GCT). Stem cell factor was not expressed at the mRNA leve
l in tissue from either subtype of GCT as determined by Northern blot
analysis; however, the protein was detected immunohistochemically in t
he cytoplasm of rare tumor cells.