TonB cells and isoform-specific anti-STAT5 shRNAs.

<p>(A) TonB cells were cultured in IL-3 (IL-3), IL-3 plus 1 µM imatinib mesylate (IL-3+IM) IL-3+ Ruxolitinib, without IL-3 (Starvation), with IL-3 plus doxycycline (IL-3+BCR-ABL), with IL-3 and doxycycline and imatinib mesylate (IL-3+BCR-ABL+IM), with doxycycline (BCR-ABL) and with doxycycline plus 1 µM imatinib mesylate (BCR-ABL+IM) for 72 hours before viable cells were counted by Trypan-blue dye exclusion. Results are shown as a percentage of control (TonB cells in the presence of IL-3). (B) TonB cells were lentivirally transduced with shRNAs targeting control (shGL2), STAT5A/B (shS5A/B, targeting both isoforms), murine STAT5A (sh-muS5A), murine STAT5B (sh-muS5B), and a mixture of both. Four days after transduction protein expression of both STAT5 isoforms and Tubulin was analyzed by western blotting. The numbers indicate changes in protein expression in % as determined by densitometry.