Search results for " breast cancer stem-like cells"
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The analysis of estrogen receptor-α positive breast cancer stem-like cells unveils a high expression of the serpin proteinase inhibitor PI-9: Possibl…
2016
Abstract Breast cancer stem cells seem to play important roles in breast tumor recurrence and endocrine therapy resistance, although the underlying mechanisms have not been well established. Moreover, in some tumor systems the immunosurveillance failure against cancer cells has been related to the presence of the granzyme B inhibitor PI-9. This study explored the status of PI-9 in tumorspheres isolated from estrogen receptor-α positive (ERα+) breast cancer MCF7 cells. Studies were performed in tertiary tumorspheres which possess high levels of stemness markers (Nanog, Oct3/4 and Sox2) and self-renewal ability. The exposure to estrogens (17-β estradiol and genistein) increased the number and…
Possible regulatory mechanisms responsible for the high expression of serpin protease inhibitor PI-9 in ER+ -derived breast cancer stem cells.
2015
Breast cancer (BC) is the most common endocrine cancer and the second leading cause of cancer-related death in women. About 75% of BCs expresses high levels of estrogen receptors that sustain the tumor growth. Moreover, in BC estrogens prevent apoptosis induced by granzyme B released by cytotoxic T lymphocytes and NK cells through the production of the granzyme B inhibitor PI-9. As a consequence, cancer cells acquire the ability to escape immune surveillance’s signaling. Although some studies explored the role of PI-9 in BC cells, its presence has not been investigated in cancer stem cells so far. In this research, tertiary tumorspheres were obtained from estrogen receptor-alfa positive (ER…