Fig. 3

Doxycycline-induced Pin1 downregulation in HL-60- and U937-Tet ON cells suppress clonogenicity in vitro. a, b Using Tet-On system, we generated inducible-shPin1 HL-60 (a) or U937 (b) cells. The effects of Pin1 downregulation were assayed by immunoblotting after Dox treatment (1 mg/ml) for 3 days. c–f Cells were cultured in normal medium supplemented with methylcellulose for 1 or 2 weeks. When colonies became visible, the morphology of cells were taken by transmission electron microscopy (c), followed by staining with p-iodonitrotetrazolium violet for counting (d). The number (e) and area (f) of colonies was measured and counted using ImageJ. Results present the mean ± SD of three independent experiments. Statistically significant differences using Student’s t test are indicated by p values. (*p < 0.05, **p < 0.01, ***p < 0.001)