Fig. 2

Proteins found to be affected upon siRNA-mediated knock-down of LRP/LR using the Proteome Profiler Antibody Arrays™ in late (DLD-1) stage colorectal cancer cells. (a) Densitometric analysis of the phospho-MAPK Proteome Profiler Antibody Array™ revealed that several proteins were affected upon siRNA-mediated knock-down of LRP/LR. When compared to non-transfected cells, Chk-2, β-catenin and AMPKα2 were found to have significant differences. The following proteins namely: CREB, p53, FAK, AMPK α1, Akt 1/2/3, STAT2 and p27 also displayed differences in expression however, these differences were found to be non-significant. (b) Densitometric analysis of the MAPK Proteome Profiler Antibody Array™ showed that CREB, GSK-3α/β and p53 were up-regulated once LRP/LR was down-regulated however, this up-regulation was found to be non-significant. c) Non-transfected and transfected DLD-1 cell lysates were incubated on the Human Apoptotic Proteome Profiler Antibody membrane arrays. Upon densitometric analysis, it was found that several anti-apoptotic proteins were decreased while several pro-apoptotic proteins were increased, including p53 phosphorylated sites, confirming the result of the MAPK array. All data shown are from 10-min exposure times. Signals for each protein are displayed as a pair of spots, with three pairs of dark reference spots on the lower left, upper right and upper left corners for alignment. PBS spots (designated regions that had consistent background with no capture sites) were used as the negative control where each value was subtracted from PBS and divided by its corresponding reference spot. All graphs represent experiments performed in duplicate with two technical repeats. *p < 0.05, **p < 0.01, ***p < 0.001, significant: The One-way ANOVA was significant, and a Bonferroni corrected post-hoc t-test was performed