Fig. 2

Claudin-4 promotes tumor cell survival. SKOV3, OVCAR3, SKOV3_contKD, and SKOV3_cld4KD cells were treated with 400 μM control peptide (“cont peptide”), 400 μM claudin mimic peptide (“DFYNP”), 2 μM staurosporine (“SS”, known inducer of apoptosis) or DFYNP + staurosporine (“DFYNP + SS”) for 18 h before being fixed and stained with dapi (to identify nuclei) and fluorescent antibody directed to active caspase-3. Representative fluorescent images of nuclei (dapi staining) and activated caspase-3 for each treatment group are shown for the claudin-4 expressing and claudin-4 knockdown SKOV3 cells (a). Percent of cell population positive for casp-3 activation was plotted (b-e). Mean ± s.e.m, n = 4 per treatment group, **p < 0.01, ***p < 0.001 vs. control peptide treated and ^‡p < 0.02, ^‡‡p < 0.01, ^‡‡‡p < 0.001 for staurosporine only vs. DFYNP plus staurosporine treatment