Figure 4. Embryonic stem and retinal stem cell marker expression in stem-like cancer cells. A: Immunofluorescence confirmed that the stem-like cancer cells (SLCCs) and human embryonic stem cells (hESCs) expressed embryonic stem cell markers, such as Oct3/4 and Nanog, and the SLCCs expressed retinal stem cell markers, such as Nestin and Pax6. The nuclei were counterstained with 4',6-diamidino-2-phenylindole (blue). Scale bars=10 μm. B: Comparison of stem cell markers in hESCs and SLCCs with real-time PCR analysis. Nanog was expressed at a higher level in the hESCs (black bars) than in the SLCCs (white bars; ***p<0.001 with the Student t test), whereas Oct3/4 and CD133 were expressed at higher levels in the SLCCs (** p<0.01 with the Student t test). C: Real-time PCR quantification of retinal stem cell markers in the WERI-Rb1 line and SLCCs. Nestin and Rx were expressed at higher levels in the SLCCs (white bars; * p<0.05 with the Student t test), whereas Pax6 was expressed at a higher level in the WERI-Rb1 cells (black bars; *p<0.05 with the Student t test). The graphs show the mean±SD (n=3).