Brain Tumor Stem-Like Cells Identified by Neural Stem Cell Marker CD15

Area of Science:

• Neuro-oncology
• Cancer Stem Cell Biology
• Molecular Pathology

Background:

• Brain tumor stem cells (BTSCs) are implicated in glioma initiation and development, traditionally identified by CD133.
• CD133 expression can be variable, influenced by environmental factors like hypoxia, suggesting the existence of CD133-negative BTSCs.
• Gliomas can originate from transformed neural stem cells (NSCs), highlighting the importance of NSC markers in brain tumor research.

Purpose of the Study:

• To investigate CD15, a neural stem cell marker, as a potential marker for BTSCs.
• To evaluate the stability of CD15 expression in long-term cultured glioma cells compared to CD133.
• To characterize the stem cell properties of CD15-positive cells from astrocytoma and ependymoma.

Main Methods:

• Isolation and culture of tumor spheres from human astrocytoma and ependymoma.
• Flow cytometry and immunohistochemistry to analyze CD15 and CD133 expression.
• Assessment of stem cell properties: self-renewal, multidifferentiation, and tumor recapitulation in vivo.

Main Results:

• CD15-positive cells isolated from tumor spheres exhibited BTSC properties, including self-renewal and multidifferentiation.
• CD15 demonstrated stable expression in long-term cultured tumor spheres, whereas CD133 expression decreased over passages.
• CD15(+)CD133(-) cells displayed BTSC characteristics, indicating their presence and significance.
• CD15 expression was confirmed in a subset of human glioma samples.

Conclusions:

• CD15 is a stable and reliable surface marker for brain tumor stem cells, including CD133-negative populations.
• CD15 represents a promising marker for identifying and studying glioma stem cells.
• This research expands the understanding of BTSC heterogeneity and identification strategies.