Figure 3

ADAMDEC1 secreted by normal epithelial cells plays a positive role in apical extrusion of RasV12-transformed cells. (a) Quantitative real-time PCR analysis of ADAMDEC1 expression. MDCK-pTR GFP-RasV12 cells and MDCK cells or MDCK ADAMDEC1-shRNA1 cells were cultured separately or co-cultured at a ratio of 1:1 in the absence or presence of the NF-κB inhibitor CAPE. The relative mRNA level of ADAMDEC1 was measured by quantitative real-time PCR with GAPDH mRNA as internal control. Average values from single culture of RasV12 cells and MDCK cells (or MDCK ADAMDEC1-shRNA1 cells) are shown as black bars. Values are expressed as ratios relative to average of single cultures of MDCK and RasV12 cells. Data are mean ± SD from eight (left), three (middle), or five (right) independent experiments. ^*P < 0.05, unpaired Student’s t-test. (b) Quantitative real-time PCR analyses for ADAMDEC1 expression in MDCK cells stably expressing ADAMDEC1-shRNA1 or -shRNA2. Values are expressed as ratios relative to MDCK. Data are mean ± SD from two independent experiments. ^*P < 0.05, unpaired Student’s t-test. N.D.; not detected. (c) Effect of ADAMDEC1-knockdown on apical extrusion of RasV12 cells. MDCK-pTR GFP-RasV12 cells were co-cultured with MDCK cells or MDCK ADAMDEC1-shRNA1 or -shRNA2 cells, and at 24 h after tetracycline addition, apical extrusion of RasV12 cells was quantified. Data are mean ± SD from three independent experiments. ^*P < 0.005, two-tailed Student’s t-test.