6 research outputs found
POU5F1 (OCT3/4) identifies cells with pluripotent potential in human germ cell tumors
Human germ cell tumors (GCTs) may have variable histology and clinical
behavior, depending on factors such as sex of the patient, age at clinical
diagnosis, and anatomical site of the tumor. Some types of GCT, i.e., the
seminomas/germinomas/dysgerminomas and embryonal carcinomas (the stem cell
component of nonseminomas), have pluripotent potential, which is
demonstrated by their capacity to differentiate into somatic and/or
extraembryonic elements. Although embryonal carcinoma cells are
intrinsically pluripotent, seminoma/germinoma/dysgerminoma cells, as well
as their precursor carcinoma in situ/gonadoblastoma cells, have the
phenotype of early germ cells that can be activated to pluripotency. The
other types of GCT (teratomas and yolk sac tumors of infants and newborn,
dermoid cyst of the ovary, and spermatocytic seminoma of elderly) are
composed of (fully) differentiated tissues and lack the appearance of
undifferentiated and pluripotent stem cells. OCT3/4, a transcription
factor also known as OTF3 and POU5F1, is involved in regulation of
pluripotency during normal development and is detectable in embryonic stem
and germ cells. We analyzed the presence of POU5F1 in GCT and other tumor
types using immunohistochemistry. The protein was consistently detected in
carcinoma in situ/gonadoblasto
Stem cell factor receptor (c-KIT) codon 816 mutations predict development of bilateral testicular germ-cell tumors
Testicular germ-cell tumors (TGCTs) of adolescents and adults originate
from intratubular germ cell neoplasia (ITGCN), which is composed of the
malignant counterparts of embryonal germ cells. ITGCN cells are
characterized, among others, by the presence of stem cell factor receptor
c-KIT. Once established, ITGCN will always progress to invasiveness.
Approximately 2.5-5% of patients with a TGCT will develop bilateral
disease and require complete castration, resulting in infertility, a need
for lifelong androgen replacement, and psychological stress. To date, the
only way to predict a contralateral tumor is surgical biopsy of the
contralateral testis to demonstrate ITGCN. We did a retrospective study of
224 unilateral and 61 proven bilateral TGCTs (from 46 patients, in three
independently collected series in Europe) for the presence of activating
c-KIT codon 816 mutations. A c-KIT codon 816 mutation was found in three
unilateral TGCT (1.3%), and in 57 bilateral TGCTs (93%; P < 0.0001). In
the two wild-type bilateral tumors for which ITGCN was available, the
preinvasive cells contained the mutation. The mutations were somatic in
origin and identical in both tumors. We conclude that somatic activating
codon 816 c-KIT mutations are associated with development of bilateral
TGCT. Detection of c-KIT codon 816 mutations in unilateral TGCT identifies
patients at risk for bilateral disease. These patients may undergo
tailored treatment to prevent the development of bilateral disease, with
retention of testicular hormonal function