Sigma-2 receptor as potential indicator of stem cell differentiation

Area of Science:

• Biochemistry
• Cell Biology
• Oncology

Background:

• The sigma-2 (σ(2)) receptor is a potential biomarker for solid tumor proliferation.
• Synthetic probes targeting σ(2) receptors are being developed for cancer diagnosis and therapy.

Purpose of the Study:

• To evaluate σ(2) receptor expression in various human stem cells (SC).
• To assess the relationship between σ(2) receptor expression, cell proliferation, and stem cell potency.

Main Methods:

• Utilized a fluorescently labeled σ(2) receptor probe (SW120) to assess receptor expression in human SC.
• Measured SW120 and 5-ethynyl-2'-deoxyuridine (EdU) intensity relative to passage number and multi-potency.
• Employed confocal microscopy to observe receptor internalization and co-localization.

Main Results:

• Demonstrated significantly higher σ(2) receptor density in proliferating SC compared to lineage-restricted cells.
• Observed σ(2) receptor internalization via receptor-mediated endocytosis in SC.
• Confirmed SW120 co-localization with lysosome markers in all imaged SC.

Conclusions:

• σ(2) receptors are highly expressed in proliferating stem cells.
• These findings suggest σ(2) receptors may be valuable for monitoring stem cell differentiation in experimental settings.