Increased expression of Rab21 in epirubicin resistant PC-3 cells. (A) The mRNA expression level of Rab21 was quantified by RT-PCR and normalised against B2M expression level. (B) Rab21 protein expression was determined by Western immunoblotting using Rab21 specific antibody. Ponceau S staining was used as a loading control. (C) Normalised expression of Rab21 protein in PC-3/Res cells represented as percentage of PC-3/Wt level. (D) Protein expression levels of Rab21 and ABCC1 in control and Rab21 siRNA transfected PC-3/Res cells.