Figure 3.
Hh effects on mammospheres are mediated by hBmi-1. Columns, mean; bars, SD. *, P < 0.05; &, P < 0.05, statistically significant differences from the control group or untreated group, respectively. A, hBmi-1 mRNA level in mammospheres compared with that in differentiated mammary cells. B, effects of hedgehog signaling on hBmi-1 mRNA level. C, effects of Bmi-1 overexpression on mammosphere number and size. D, effects of Bmi-1 knockdown on mammosphere number and size. Primary mammospheres were infected with the control virus (GFP alone) or siRNA lentiviruses (hBmi-1-siRNA1-GFP, hBmi-1-siRNA2-GFP, and hBmi-1-siRNA3-GFP), or uninfected (Non) as the control, and cultured in suspension in the absence (untreated) or presence of 3 μg/mL Shh for 7 days. The total number of mammospheres formed from 10,000 single cells and the total cells per mammosphere were counted. The single cells dissociated from each group of primary mammospheres were grown as secondary mammospheres in suspension for 7 to 10 days without treatment.