PUBLICATION

Phenotypical and Pharmacological Characterization of Stem-Like Cells in Human Pituitary Adenomas

Authors
Würth, R., Barbieri, F., Pattarozzi, A., Gaudenzi, G., Gatto, F., Fiaschi, P., Ravetti, J.L., Zona, G., Daga, A., Persani, L., Ferone, D., Vitale, G., Florio, T.
ID
ZDB-PUB-160816-23
Date
2017
Source
Molecular neurobiology   54(7): 4879-4895 (Journal)
Registered Authors
Keywords
Cancer stem cells, Cell proliferation, Pituitary adenoma, Somatostatin receptors, Spherogenesis
MeSH Terms
  • AC133 Antigen/metabolism
  • Adenoma*/metabolism
  • Animals
  • Cell Differentiation
  • Humans
  • Mice, SCID
  • Neoplastic Stem Cells/cytology*
  • Pituitary Gland/pathology*
  • Pituitary Neoplasms/metabolism
  • Pituitary Neoplasms/pathology*
  • Somatostatin
  • Tumor Cells, Cultured
PubMed
27514754 Full text @ Mol. Neurobiol.
Abstract
The presence and functional role of tumor stem cells in benign tumors, and in human pituitary adenomas in particular, is a debated issue that still lacks a definitive formal demonstration. Fifty-six surgical specimens of human pituitary adenomas were processed to establish tumor stem-like cultures by selection and expansion in stem cell-permissive medium or isolating CD133-expressing cells. Phenotypic and functional characterization of these cells was performed (1) ex vivo, by immunohistochemistry analysis on paraffin-embedded tissues; (2) in vitro, attesting marker expression, proliferation, self-renewal, differentiation, and drug sensitivity; and (3) in vivo, using a zebrafish model. Within pituitary adenomas, we identified rare cell populations expressing stem cell markers but not pituitary hormones; we isolated and expanded in vitro these cells, obtaining fibroblast-free, stem-like cultures from 38 pituitary adenoma samples. These cells grow as spheroids, express stem cell markers (Oct4, Sox2, CD133, and nestin), show sustained in vitro proliferation as compared to primary cultures of differentiated pituitary adenoma cells, and are able to differentiate in hormone-expressing pituitary cells. Besides, pituisphere cells, apparently not tumorigenic in mice, engrafted in zebrafish embryos, inducing pro-angiogenic and invasive responses. Finally, pituitary adenoma stem-like cells express regulatory pituitary receptors (D2R, SSTR2, and SSTR5), whose activation by a dopamine/somatostatin chimeric agonist exerts antiproliferative effects. In conclusion, we provide evidence that human pituitary adenomas contain a subpopulation fulfilling biological and phenotypical signatures of tumor stem cells that may represent novel therapeutic targets for therapy-resistant tumors.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping