Oral Presentation New Zealand Association of Plastic Surgeons ASM & AGM

Embryonic stem cell-like populations are present within Schwannoma (1250)

Ethan J Kilmister 1 , Josie Patel 1 , Nicholas Bockett 1 , Bridget Chang-McDonald 1 , Dalice Sim 1 , Agadha Wickremesekera 1 2 3 , Paul F Davis 1 , Swee T Tan 1 2 4
  1. Gillies McIndoe Research Institute, Wellington, New Zealand
  2. Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Victoria, Australia
  3. Department of Neurosurgery, Wellington Regional Hospital, Wellington, New Zealand
  4. Wellington Regional Plastic, Maxillofacial and Burns Unit, Hutt Hospital, Wellington, New Zealand

Aim: Embryonic stem cell (ESC)-like cells have been demonstrated in many benign and malignant tumors. This study aimed to identify ESC-like cells in Schwannoma using the induced-pluripotent stem cell (iPSC) markers OCT4, SOX2, NANOG, KLF4 and c-MYC.

Methods: Immunohistochemical staining (n=20) and RT-qPCR (n=6) were performed on Schwannoma tissue samples to investigate protein and mRNA expression of these iPSC markers, respectively. Immunofluorescence staining (n=2) was performed to investigate co-localization of the iPSC markers with CD34, α-SMA and CD133.

Results: Immunohistochemical staining and RT-qPCR demonstrated protein and mRNA expression of all five iPSC markers, in all Schwannoma tissue samples investigated, respectively. Immunofluorescence staining showed expression of SOX2, KLF4 and c-MYC on the tumor cells and the endothelium of the tumor microvessels which also expressed OCT4, while NANOG was exclusively expressed on the endothelium of the tumor microvessels. The OCT4+/CD34+ endothelium expressed CD133.

Conclusions: We have identified an OCT4+/SOX2+/NANOG+/KLF4+/c-MYC+/CD133+ ESC-like subpopulation on the endothelium of tumor microvessels and an OCT4-/SOX2+/NANOG-/KLF4+/c-MYC+/CD133+ ESC-like subpopulation within Schwannoma. We speculate that the OCT4+/SOX2+/NANOG+/KLF4+/c-MYC+/CD133+ population may be the origin of this tumor.