Comparative analysis of targeting key genes in stat pathway in k562 cells

BCR-ABL is one of the main mutation found in Chronic Myeloid Leukemia (CML). It is said to activate STAT5 and in turn activate BCL-XL (BCL2L1). In the past, researchers have silenced these genes separately but a comparative analysis among them has never been done to find out the best target to induce apoptosis.
In the present study, the effects of downregulating BCR-ABL, STAT5A, STAT5B and BCL-XL in human chronic myeloid leukemia cell line (K562 cells) were investigated through RNA interference (RNAi) and the proliferation inhibition and apoptosis induction were analyzed thereafter. K562 cells were transfected with various concentrations of siRNA and the expressions of aforesaid genes were determined by reverse transcription - quantitative polymerase chain reaction (RT-PCR) and Western blot analysis. K562 cell proliferation and apoptosis were analyzed using MTT and flow cytometry respectively.
RT-PCR and western blotting results post siRNA transfection confirmed the targeted gene suppression and protein reduction in the cell. The cell proliferation assay and apoptosis assay revealed that silencing BCL-XL had the highest killing effect on K562 cells as compared to knocking down BCR-ABL, STAT5A and STAT5B. A further all four gene expression profile study validated the formerly known direct dependency of BCL-XL on BCR-ABL via STAT5 in CML.