Fig. 4

The effect of siRNA-mediated LRP knock-down on caspase-3, − 8 and − 9 activity in early (SW-480) and late (DLD-1) stage colorectal cancer cells. a) Upon treatment of SW-480 and DLD-1 cells with siRPSA #1, a significant 4-fold and 5-fold increase in caspase-3 activity was revealed, respectively, in comparison to cells that were not transfected (set to 100%). Both cell lines showed no significant difference in caspase-3 activity between cells transfected with negative control esiRNA-RLUC and non-transfected cells. PCA was used as a positive control. SW-480:***p = 0.0007 and DLD-1: **p = 0.0059. N.S: p > 0.05, non-significant. b) siRPSA #1 transfected SW-480 and DLD-1 cells both displayed a 4-fold significant increase in caspase-8 activity, compared to cells that were not transfected (set to 100%). Both cell lines showed no significant difference in caspase-8 activity between cells transfected with the esiRNA-RLUC and non-transfected cells. SW-480: **p = 0.0083 and DLD-1: **p = 0.002. N.S: p > 0.05, non-significant. C) SW-480 and DLD-1 cells transfected with siRPSA #1 showed a significant 7-fold increase and 4-fold increase, respectively, in contrast to cells that were not transfected. Both cell lines showed no significant difference in caspase-9 activity between cells transfected with the esiRNA-RLUC and non-transfected cells. SW-480:***p = 0.0001 and DLD-1: ***p = 0.0008. N.S.: p > 0.05, non-significant. This data represents three biological replicates which were completed in triplicate