Induced Expression of Cancer Stem Cell Markers ALDH1A3 and Sox-2 in Hierarchical Reconstitution of Apoptosis-resistant Human Breast Cancer Cells

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.

ALDH1A3 Is the Key Isoform That Contributes to Aldehyde Dehydrogenase Activity and Affects in Vitro Proliferation in Cardiac Atrial Appendage Progenitor Cells

“…Annexin V-staining suggests that ALDH hi cells may be more apoptosis-resistant than ALDH lo ones. Higher apoptosis-resistance of ALDH hi vs. ALDH lo cells has been reported in various cancer stem cells ( 43 – 45 ). Silencing ALDH1A by siRNA or shRNA in human melanoma cancer stem cells led to cell cycle arrest, apoptosis and decreased cell viability in vitro and reduced tumorigenesis in vivo ( 45 ).…”

“…Several studies showed that ALDH1A3 is a cancer stem cell gene. ALDH1A3 expression was detected in 78% of small-sized Ki-67 + proliferating progenitor cells in the human breast cancer cell line HCC1937 ( 43 ). Most recently, ALDH1A3 was shown to affect colon cancer in vitro proliferation and invasion depending on CXCR4 status ( 49 ).…”

Stem-like Human Breast Cancer Cells Initiate Vasculogenic Mimicry on Matrigel

“…ALDH1A3, one of the subtypes of the ALDH family, was proposed as a novel clinical CSC marker showing a clear correlation between CSC prevalence and the development of metastatic breast cancer [8, 38]. ALDH1A3 was found to be expressed in not only CSCs but also highly proliferating progenitor cells in TNBC [20]. Sox-2 (Sex-determining region Y (SRY)-box binding protein-2) plays an important role in the maintenance of the pluripotent stem cell state and regulation of embryonic development [2, 4, 44, 57, 58], and is associated with breast CSCs [26].…”

Ginseng polysaccharide inhibits MDA‑MB‑231 cell proliferation by activating the inflammatory response

“…Apoptosis is one of the pathways of cell death; however, cancer cells survival is promoted by the induction of an apoptosis resistance mechanism ( 59 ). A previous study reported that aldehyde dehydrogenase family 1 member A3 (ALDH1A3) and sex determining region Y box 2 (Sox-2) regulated the mechanism of apoptosis resistance in BC cells ( 60 ); however, GPS-mediated regulation of ALDH1A3 and Sox-2 has not been reported. TNF-α is a mediator of inflammation and is a member of a family of >20 related proteins including lymphotoxin-a, CD30 ligand, CD40 ligand, Fas ligand and TRAIL ( 61 ).…”