Figure 3
SOX2 induces stem cell properties in HNSCC cells in vitro. (A) Expression of induced stemness-associated factors – OCT4 and NANOG – determined by western blot analysis. (B) Representative photos showing the morphology of spheres grown in serum-free cultures (left). The number of neurospheres (>10 μm) generated from control and SOX2-overexpressing SNU1041 cells grown in a serum-free culture medium for 14 days (right); scale bar, 10 μm. Cells were seeded in a 24-well plate at a density of 200 cells per well and cultured in serum-free media with EGF and bFGF commitment every second day. Spheres with a diameter exceeding 10 μm were counted after 14 days. (C) Flow cytometric analysis showed a moderate increase in CD44-positive population in control cells and in SOX2-overexpressing SNU1041 cells. IgG was used as a negative control. Cells were dissociated into a single-cell suspension, labelled with an anti-CD44 primary antibody, and then subjected to flow cytometric analysis on a FACSCalibur instrument.
