Figure 2.

Resistant mutations identified in the ruxolitinib screen transform the Ba/F3 cells and display constitutive activation of JAK2 and STAT5: Mutations identified from 4 and 8μM screen were cloned in JAK2-V617F background either as single mutation or compound mutations and stably expressed in Ba/F3 cells by retroviral gene transfer method. The transformation ability of the mutant JAK2s was measured using MTS- based method after 72hrs without IL-3 (n=3). JAK2-Y931C showed enhanced cell growth compared to JAK2-V617F, whereas the remaining JAK2 mutants showed equal transformation ability (A). **p<0.01. Western blot analysis was performed using Ba/F3 cells expressing the JAK2 mutants and measured the activation of JAK2 and STAT5 (B). A representative image of n=2 two independent experiments is shown.