To simultaneously measure the activities of multiple TFs, a Cancer Stem Cell TF activation profiling plate array (FA-1004; Signosis, Santa Clara, CA, USA) was used. Briefly, biotin-labeled probes containing consensus sequences of TF DNA-binding sites were incubated with nuclear extracts that were prepared by nuclear extraction kit (SK-0001; Signosis) for 30 min at 25°C. The TF/probe complex mixtures were separated by spin column purification. The bound probes were detached from the complex using elution buffer and centrifuged at 9,800 ×g for 2 min. After the eluents were denatured at 98°C for 5 min, the denatured sample was added to TF hybridization buffer. The resulting mixture (100 μL) was added to each well of the hybridization plate, and the plate was sealed with aluminum adhesive and incubated at 42°C for 16 h. The captured DNA probe was further detected using a streptavidin-horseradish peroxidase conjugate. Endpoint luminescence readings of the samples were observed using Fluostar omega (BMG Labtech, Ortenberg, Germany).