Embryonic stem cell-like subpopulations are present within Schwannoma

Area of Science:

• Oncology
• Stem Cell Biology
• Neurosurgery

Background:

• Accumulating evidence suggests embryonic stem cell (ESC)-like cells exist in benign tumors.
• Schwannomas are common nerve sheath tumors, and their cellular origins are not fully understood.

Purpose of the Study:

• To identify ESC-like cells within Schwannoma tissue.
• To investigate the expression of induced-pluripotent stem cell (iPSC) markers (OCT4, SOX2, NANOG, KLF4, c-MYC) in Schwannoma.

Main Methods:

• Immunohistochemical (IHC) staining and RT-qPCR were used to detect protein and mRNA expression of iPSC markers in Schwannoma tissue samples (n=20 for IHC, n=6 for RT-qPCR).
• Immunofluorescence (IF) staining was employed to examine the co-localization of iPSC markers with specific cellular markers (CD34, α-SMA, CD133).

Main Results:

• All five iPSC markers (OCT4, SOX2, NANOG, KLF4, c-MYC) were detected at both the protein and mRNA levels in Schwannoma.
• IF staining revealed expression of SOX2, KLF4, and c-MYC in tumor cells and microvessel endothelium; OCT4 was also found in the endothelium.
• NANOG was exclusively detected in the microvessel endothelium, which also expressed CD133 and OCT4.

Conclusions:

• This study identified putative ESC-like subpopulations within Schwannoma.
• One subpopulation, OCT4+/SOX2+/NANOG+/KLF4+/c-MYC+/CD133+, was located on the endothelium of tumor microvessels.
• A second subpopulation, OCT4-/SOX2+/NANOG-/KLF4+/c-MYC+/CD133+, was also found within the Schwannoma.