Changes of stem cell niche during experimental pituitary tumor development

SOSA, LILIANA DEL VALLE; VELAZQUEZ, FABIOLA NOELIA; MUKDSI, JORGE HUMBERTO; GUIDO, CAROLINA BEATRIZ; ZLOCOSWKI, NATACHA; PETITI, JUAN PABLO; PEREZ, PABLO ANÍBAL; GUTIERREZ, SILVINA; TORRES, ALICIA INÉS

JOURNAL OF NEUROENDOCRINOLOGY.

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021

0953-8194

To investigate the putative stem cell/tumor stem cell (SC/TSC) niche contribution tohyperplasic/adenomatous pituitary lesions, we analyzed variation in the pituitary stemcell population during the development of experimental pituitary tumors. Pituitarytumors were induced in female F344 rats with estradiol benzoate for 5, 10, 20 and30 days. Cells positive for GFRa2, Sox2, Sox9, Nestin, CD133 and CD44 were identified in the marginal zone and in the adenoparenchyma in both control and 30D groups,with predominant adenoparenchyma localization of GRFa2 and SOX9 found in tumoralpituitaries. GFRa2, Nestin, CD133 and CD44 were upregulated at the initial stagesof tumor growth, whereas Sox9 significantly decreased at 5D, with Sox2 remaininginvariable during the hyperplasic/adenomatous development. In addition, isolated pituispheres from normal and tumoral pituitary glands enriched in SC/TSC were characterized. Pituispheres from the 30D glands were positive for the above-mentionedmarkers and showed a significant increase in the proliferation. In conclusion, our datarevealed pituitary SC pool fluctuations during hyperplastic/adenomatous development, with differential localization of the SC/TSC niche in this process. These findingsmay help to provide a better understanding of these cell populations, which is crucialfor achieving advancements in the field of pituitary tumor biology.