SiRNA-mediated knockdown of PTBP1, but not hnRNP C, inhibits imatinib-induced apoptosis in CML cells.

<p>(A) K562 cells were nucleofected with either control or PTBP1-specific siRNA duplexes. 24 hours later, these cells were treated with increasing doses of imatinib (0, 0.25, 0.5 µM). The cells were harvested after another 24 hours and western blot was performed to determine the protein levels of PTBP1, PARP, cleaved caspase 3 and BIM. Equal loading in each lane was determined by blotting of GAPDH. (B) The same experiment was performed as described in (A). The only difference was that siRNA duplexes against hnRNP C were used instead of PTBP1-specific siRNA duplexes.