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Expression of Aminopeptidase A in Human Gestational Choriocarcinoma Cell Lines and Tissues
- Source :
- Placenta. 21:63-72
- Publication Year :
- 2000
- Publisher :
- Elsevier BV, 2000.
-
Abstract
- Aminopeptidase A (AP-A), a cell-surface metallopeptidase hydrolyzing peptide with N-terminal acidic residues, has been proved to be identical to the B cell differentiation antigen BP-1 and to the kidney differentiation antigen gp160, suggesting recognition of AP-A as a differentiation-related marker on certain normal and transformed cells. AP-A has also been purified from human placenta and been shown to be localized in the trophoblasts. In the present study, we examined the expression and enzymatic activity of AP-A in human gestational choriocarcinoma, a neoplastic transformant from trophoblasts which comprises a heterogenous population of trophoblastic cells in different stages of differentiation. Flow cytometry and immunoblot analysis demonstrated that AP-A was expressed in five choriocarcinoma cell lines which were secreting low or moderate levels of human chorionic gonadotropin (hCG), while two high hCG-secreting cell lines lacked AP-A expression. The AP-A enzymatic activity correlated with cell-surface levels of AP-A and was abrogated by amastatin, an inhibitor of AP-A. Immunohistochemical analysis revealed that AP-A was present in seven of eight choriocarcinoma tissues and was localized on the cell membrane of cytotrophoblastic choriocarcinoma cells, but not on cells with syncytiotrophoblast-like features. These results demonstrate that AP-A is expressed on most choriocarcinomas and its expression is restricted to low hCG-secreting, cytotrophoblastic cells and down-regulated as a function of cell differentiation, suggesting an involvement of AP-A in the differentiation/maturation process of neoplastic trophoblasts.
- Subjects :
- medicine.medical_specialty
Cellular differentiation
Immunoblotting
Molecular Sequence Data
Biology
Glutamyl Aminopeptidase
Aminopeptidases
Chorionic Gonadotropin
Gestational choriocarcinoma
Human chorionic gonadotropin
Mice
Chorioepithelioma
Pregnancy
Internal medicine
Tumor Cells, Cultured
medicine
Animals
Humans
Amino Acid Sequence
Choriocarcinoma
Enzyme Inhibitors
reproductive and urinary physiology
B cell
Cell growth
Cell Membrane
Antibodies, Monoclonal
Obstetrics and Gynecology
Cell Differentiation
Flow Cytometry
medicine.disease
Immunohistochemistry
Molecular biology
female genital diseases and pregnancy complications
medicine.anatomical_structure
Endocrinology
Reproductive Medicine
Cell culture
Uterine Neoplasms
embryonic structures
Female
Cell Division
Developmental Biology
Subjects
Details
- ISSN :
- 01434004
- Volume :
- 21
- Database :
- OpenAIRE
- Journal :
- Placenta
- Accession number :
- edsair.doi.dedup.....1e1e9f6ab32834f48a45c1bc85f72482