Embryonic Stem Cell-like Population in Hypertrophic Port-wine Stain

Abstract

Objective: To identify and characterize an embryonic stem cell (ESC)-like population within hypertrophic port-wine stain (HPWS). Methods: HPWS tissue samples from 15 patients underwent immunohistochemical staining for induced pluripotent stem cell (iPSC) markers OCT4, SOX2, NANOG, KLF4, and c-MYC. Immunofluorescence staining was performed on 2 of these tissue samples to investigate colocalization of these markers. In situ hybridization and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) were performed on 6 of the HPWS samples to investigate transcript expression of these iPSC markers. Western blotting and RT-qPCR were performed on 3 HPWS-derived primary cell lines, to determine protein and transcript expression of these markers, respectively. Results: Immunohistochemical staining demonstrated expression of OCT4, SOX2, KLF4, and c-MYC but not NANOG on the endothelium and media of lesional vessels and on cells within the stroma in all 15 HPWS tissue samples. Immunofluorescence staining showed the presence of an OCT4+/SOX2+/NANOG-/KLF4+/c-MYC+ ESC-like subpopulation within the endothelium and media of the lesional vessels, and cells within the stroma of HPWS. In situ hybridization detected OCT4, SOX2, KLF4, and c-MYC transcripts in all 6 HPWS tissue samples. RT-qPCR demonstrated transcripts of all 5 iPSC markers in the HPWS tissue samples and in the HPWS-derived primary cell lines, which expressed OCT4, SOX2, KLF4, and c-MYC but not NANOG proteins by Western blotting. Conclusion: This study demonstrated an OCT4+/SOX2+/NANOG-/KLF4+/c-MYC+ ESC-like population within the endothelium and media of the lesional vessels and the cells within the stroma of HPWS.