Figure 2. ErbB3 knockdown rescues hyperproliferation and polarized morphogenesis of Caco-2 cells expressing oncogenic K-Ras.

A. Caco-2tet K-Ras^G12V cells were transfected with non-targeting (siNT) and ErbB receptor-specific siRNAs, respectively. The next day cells were seeded into 3D culture. One day post seeding K-Ras^G12V expression was induced with dox. Two days later CTX was added. Cultures were fixed the next day and stained with DAPI (nuclei; blue), anti-aPKC antibody (cyan) and phalloidin (F-actin; red). GFP is co-expressed with K-Ras^G12V (green). Shown are confocal sections of the midplane of representative cysts (scale: 20 μm). B. The percentage of cysts with PSAL from (A) was determined (n>70; N=3). C. The number of nuclei in the midplane of cysts from (A) was counted (n=25; N=3). D. Two days after gene silencing, lysates were generated and analyzed by immunoblotting using the indicated antibodies. Tubulin was detected as a loading control. Specific bands are marked by arrowheads.