Objective: To investigate the mechanism of STI571 inducing apoptosis of K562 cells which express P210(BCR/ABL).
Methods: Apoptosis was analyzed by Annexin-V/PI, DioC6 [3] staining, DCFH-DA staining, DNA-PI staining and DNA ladder. Western blot was used to analyse mitochondrial and cytosolic cyto C, Bcl-X(L), caspase-3, actin protein and the level of tyrosine phosphorylation.
Results: After exposure to STI571, K562 cells were induced to apoptosis. Tyrosine phosphorylation level of P210(BCR/ABL) and Bcl-X(L) was decreased. Caspase-3 was activated and there was an cytosolic accumulation of cyto C.
Conclusion: STI571 could rapidly decrease the tyrosine phosphorylation level of P210(BCR/ABL). The signal pathway mediated by the cytosolic translocation of mitochondrial cyto C was one of the mechanisms that STI571 inducing apoptosis. STI571 was an effective gene targeting therapeutic agent.