Fig. 5.

Simvastatin induces apoptosis and downregulates JAK2/STAT5 activation in JAK2-V617F-dependent cells. (A) HEL cells were treated with 0 (DMSO, 0·1%), 1 μmol/l, and 5 μmol/l simvastatin for 24 and 48 h and stained with Annexin V and analysed by flow cytometry to detect Annexin V-positive cells. Error bars indicate standard deviation of triplicate samples. This experiment was performed four times with similar results. (B) Immunoblot analysis to detect PARP cleavage after 0 (DMSO, 0·1%), 1 μmol/l, and 5 μmol/l simvastatin treatment of HEL (top blot) and SET-2 (bottom blot) cells for 24 and 48 h. Arrows indicate migration of cleaved PARP. (C) HEL, SET-2, and K562 cells were treated with 5 μmol/l simvastatin for 4 d and cellular lysates were analysed by immunoblotting for P-JAK2, JAK2, P-STAT5, STAT5, and HSP90 (as an additional loading control), as indicated.