Regulation of Mcl-1 by SRSF1 and SRSF5 in Cancer Cells
Figure 5
Knockdown of RNA binding proteins and their effect on the protein levels of Mcl-1 splice isoforms.
(A) MCF-7 cells were transfected with SRSF1 (1 and 2), SRSF5 (1 and 2), GAPDH (G) and Negative control (NC) siRNAs, or treated with vehicle (lipid) only (V), or were untreated (UT). SRSF1, 5, Mcl-1 and GAPDH protein levels were determined by immunoblotting 72 hours after transfection with the siRNAs, using 30µg of total cell lysate. Histograms show densitometric analysis of Mcl-1L and Mcl-1S protein expression. Data are shown as the mean ± SEM. ** indicates P≤0.01; * indicates P<0.05. (B) JAR cells were transfected with SRSF1 (1 and 2), GAPDH (G) and Negative control (NC) siRNAs, or treated with vehicle (lipid) only (V), or were untreated (UT). SRSF1, Mcl-1 and GAPDH protein levels were determined by immunoblotting 72 hours after transfection with the siRNAs, using 30 µg of total cell lysate. (C) After transfection with SRSF1 (1) and NC siRNA MCF-7 cells were treated with 200 µM etoposide or DMSO control for 6 hours. Induction of apoptosis was assessed by measuring caspase3/7 activity.* indicates P<0.05.