FIGURE 4.
Effect of transient knockdown of cPAcP by siRNA in LNCaP C-33 cells on tyrosine phosphorylation of ErbB-2. A, lysate proteins of transiently transfected cells with different amounts of PAcP siRNA-126 plasmids for 48 h were analyzed for cPAcP, cyclin D1, PCNA, and the phosphorylation (p) levels of ErbB-2, p52Shc, ERK1/2, Akt, Src, STAT3, and STAT5 proteins. After stripping the membrane, the protein levels of ErbB-2, Shc, ERK1/2, Akt, Src, STAT3, STAT5, and α-tubulin were detected, respectively. Similar results were obtained from five sets of independent experiments. B, LNCaP C-33 cells were plated at a cell density of 3 × 105/well in 6-well plates for 48 h and then transfected with different amounts of PAcP siRNA-126 plasmids. Control cells were transfected with the vector containing scramble oligonucleotides. Cell numbers were counted 3 days after transfection. The ratio of cell growth was calculated by normalizing the cell number to that of the control. The result shown is the average from three sets of independent experiments in duplicates (n = 2 × 3). Bars = S.E.