Fig. 4

The effect of Baicalein on IM resistance of CML CD34⁺ cells within microenvironment. A Effects of Baicalein on proliferation of K562 CD34⁺ cells were measured by MTT analysis. The cells were treated with various concentrations of Baicalein for 36 h in the supernatant of hBMSCs. B, C K562 CD34⁺ cells and primary CML CD34⁺ cells were exposed to 0.5 μM IM within various concentrations of Baicalein for 36 h in co-culture model, respectively. JAK2/STAT5 signaling pathway was determined by Western blot in treated CML CD34⁺ cells in co-culture model. D Nuclear translocalization of p-STAT5^Tyr694 (green) was acquired by confocal microscopy after staining the indicated antibody, when K562 CD34⁺ cells treated with or without 20 μM Baicalein in 0.5 μM IM-induced co-culture model. Scale bar, 10 μm. E K562 CD34⁺ cells and primary CD34 + CML cells were cultured with or without hBMSCs for 12 h and then treated with or without 0.5 μM IM within various concentrations of Baicalein for 36 h, respectively. Apoptosis was assessed by Annexin V-PI double staining after treatment in co-culture model. F, G K562 CD34⁺ cells and primary CML CD34⁺ cells were cultured with or without hBMSCs for 12 h and then treated with the combination of 0.5 μM IM and Baicalein for 36 h in co-culture model, respectively. STAT5 DNA binding activity was assessed by EMSA. H Soft-sugar-colony forming experiment was performed to ascertain Baicalein reversal effect after treatment with or without 0.5 μM IM or the combination