Fig. 1

Spheres from BE(2)-C cells. a BE(2)-C cells were cultured either in a 10% serum adherent condition for 3 days (parental cells) or in a serum-free non-adherent condition over 4 weeks (spheres) and examined by phase-contrast microscopy. The images shown are representative of three independent experiments. Scale bars show 100 μm. b Total RNA was prepared from parental cells and spheres. The relative mRNA expression of nanog homeobox (NANOG), octamer-binding transcription factor 4 (OCT4), Cu²⁺-transporting ATPase alpha polypeptide (ATP7A), and dickkopf homolog 2 (DKK2) to phosphoglycerate kinase 1 (PGK1) was analyzed by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). The mean expression in parental cells was set at 1. The data shown are means ± SD of three independent experiments