Monoclonal mouse anti

Western blot analysis was carried out, as previously described (18 (link)). monoclonal mouse anti-FOXM1, monoclonal mouse anti-CD133 and monoclonal mouse anti-CD44 (Cell Signaling Technology, Inc., Danvers, MA, USA), as well as monoclonal mouse anti-aldehyde dehydrogenase 1 (ALDH1) and monoclonal mouse anti-β-actin (Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA) antibodies were used as primary antibodies. The cells were lysed by being incubated in lysis buffer for 20 min at 4°C. The protein concentration was determined using the Bio-Rad assay system (Bio-Rad, Hercules, CA, USA). Total proteins were fractionated using SDS-PAGE and transferred onto a polyvinylidene fluoride membrane (Millipore, Billerica, MA, USA). Signals were detected using an Enhanced Chemiluminescence Advance western blot analysis system (Amersham Pharmacia Biotech Inc., Piscataway, NJ, USA).