Differential effects of bortezomib on survivin in HCT116p53-/- cells versus HCT116 cells. A. HCT116 and HCT116p53-/-. B. LNCap with wild type p53 and PC-3 with null p53. Sub-confluent cells were treated with and without bortezomib for 48 hours. Cells were then collected and lysed for western blots to determine survivin expression. Actin was used as the internal control for total lysate protein loading. The expression of survivin in wild type p53 cells was set at 1 and relative survivin expression is shown after normalization with actin.