Figure 4.

Knockdown of BMI1 suppresses CSC activity in K1 cells. K1 cells were transduced with lentiviruses carrying BMI1-specific shRNAs (shBMI1#1, shBMI1#2, or the combination #1plus #2 as a ratio of 1:1) followed by selection with 2 μg/mL puromycin for 72 h. (A,B) The mRNA (A) or protein (B) expressions of BMI1 were determined by real-time RT-PCR or Western blot, respectively. (C) The shRNA-transduced K1 cells were used for primary thyrosphere cultivation and counted the sphere numbers on Day 7. After counting, the formed primary thyrospheres were collected with 100 μm cell strainers and dissociated into single-cell suspension after treatment with HyQTase followed by secondary thyrosphere cultivation and counting at Day 7 post seeding. Scale bars: 50 μm. *, p < 0.05; **, p < 0.01.