Skip to main content
Figure 2 | Breast Cancer Research

Figure 2

From: Identification of novel molecular regulators of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in breast cancer cells by RNAi screening

Figure 2

Caspase-8, caspase-3/7, and cell-viability RNAi screens of TRAIL-induced apoptosis in MB231 cells. (A) Controls included in the RNAi screens for (i) caspase-8 activation, (ii) caspase-3/7 activation, and (iii) cell viability in the absence (white bars) or presence (black bars) of TRAIL. For assessment of caspase-8 and caspase-3/7 activation, cells were siRNA-transfected and, 48 hours later, were treated with 1,000 ng/ml TRAIL for 1 hour. For assessment of cell viability, cells were siRNA-transfected, and 48 hours later were treated with 100 ng/ml TRAIL for 17 hours. Data are normalized to the mean value of negative control siRNA (siNeg)-transfected cells in the absence of TRAIL and are shown as the mean and standard deviation for each group by using the following number of wells: cells only, between 318 and 384 wells; and siRNA-transfected between 48 and 96 wells. Comparison of TRAIL-treated with siNeg-transfected untreated cells demonstrated a significant increase in caspase-8 and caspase-3/7 activation and a decrease in viability. siCASP8 reduced caspase-8 (P = 3 × 10-21) and caspase-3/7 (P = 2.5 × 10-22) activation and increased viability (P = 1.0 × 10-48) compared with siNeg-transfected cells. siFLIP significantly increased caspase-8 (P = 7.0 × 10-5) and caspase-3/7 (P = 2.3 × 10-58) activation and decreased viability (1.0 × 10-67) compared with siNeg-transfected cells. ***P < 0.001, by using a two-tailed Student's t test. (B) Scatterplots comparing results for each siRNA (total of 4,540) in each screen in the absence of TRAIL: (i) activation of caspase-3/7 versus caspase-8, (ii) activation of caspase-8 versus cell viability, and (iii) activation of caspase-3/7 versus cell viability. (C) Scatterplots comparing results for each siRNA (total of 4,540) in each screen in the presence of TRAIL: (i) activation of caspase-3/7 versus caspase-8, (ii) activation of caspase-8 versus cell viability, and (iii) activation of caspase-3/7 versus cell viability. The trend line for each data comparison is shown as the Pearson correlation (r).

Back to article page

Breast Cancer Research

ISSN: 1465-542X

Contact us