Kashii-Magaribuchi K, Takeuchi R, Haisa Y, Sakamoto A, Itoh A, Izawa Y, Isa M, Fukuzawa M, Murakami M, Takahashi R. Induced Expression of Cancer Stem Cell Markers ALDH1A3 and Sox-2 in Hierarchical Reconstitution of Apoptosis-resistant Human Breast Cancer Cells.
Acta Histochem Cytochem 2016;
49:149-158. [PMID:
27917009 PMCID:
PMC5130344 DOI:
10.1267/ahc.16031]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 09/27/2016] [Indexed: 12/18/2022] Open
Abstract
We established an experimental system that can induce p53-dependent apoptosis by doxycycline treatment to analyze characteristics of the apoptosis-resistant cancer cell subpopulation in the human breast cancer cell line HCC1937. Expression patterns of the stem cell markers, ALDH1A3 and Sox-2, the luminal differentiation marker, GATA3 and the proliferation index marker, Ki-67 were analyzed using immunostaining and fluorescence-activated cell sorting (FACS). After doxycycline treatment, the number of viable cells was gradually decreased over seven days in a time-dependent manner due to p53-induced apoptosis; however, the number of smaller-sized ALDH1A3+ cells assessed by immunostaining increased sharply after 1 day of doxycycline treatment, suggesting their apoptosis-resistant nature. The expression of ALDH1A3 was also detected in 78% of small-sized Ki-67+ proliferating progenitor cells, followed by the transient expression of GATA3, which presumably indicated the ability to differentiate into luminal progenitor cells. Although 42.2–58.5% of residual cells were positive for both ALDH1A3 and GATA3, their expression patterns exhibited an inverse correlation. The expression pattern of another stem cell marker, Sox-2, was similar, but more drastically altered after p53 induction compared with ALDH1A3. These findings may aid in understanding the hierarchical responses of cancer stem cells to therapeutic stresses.
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