Fig. 4

Targeting claudin-4 interactions reduces tumor burden in vivo. ZsGreen-PEO4 ovarian tumor 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. a Percent of cell population positive for casp-3 activation was plotted. Mean ± s.e.m, n = 4 per treatment group, **p < 0.01, ***p < 0.001 vs. control peptide treated and ^‡‡‡p < 0.001 for staurosporine only vs. DFYNP plus staurosporine treatment. Female athymic nude mice with fluorescent ZsGreen-PEO4 human ovarian tumors were treated with 4 mg/kg control peptide or 4 mg/kg DFYNP (i.p. injection) every 48 h for three weeks. b Representative IVIS images of ovarian tumors taken before and after treatment. c Immunohistochemical analysis of claudin-4 expression in ZsGreen-PEO4 tumors in vivo. Inlay shows same section of tissue without primary antibody. d Quantitative analysis of change in photon flux, a measure of tumor size, before and after treatment. Mean ± s.e.m, n = 8-10 animals per group, *p < 0.05, ***p < 0.001 vs. control-treated