2 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
Purification process monitoring in monoclonal antibody preparation: contamination with viruses, DNA and peptide growth factors.
Administration in vivo of monoclonal antibodies to humans is challenged by considerations regarding their safety. Contamination with viruses, potentially oncogenic nucleic acids and biologically active components like growth factors and hormones forms a serious point of concern in this respect. We have investigated the potential risk of viral contamination by measuring the reduction of 12 different viruses (after spiking) in the standard downstream purification process of ascitic fluid. Depending on the type of virus added and the purification step employed, the reduction of infectious virus particles varies considerably. The overall reduction ranges from about 10(3), observed for a member of the family of Papovav