Figure 4.

STEAP vaccination prolongs survival in a prostate cancer model. Immunofluorescence of TRAMP-C2 cells was performed using a polyclonal STEAP antibody followed by a fluorescent-conjugated secondary antibody and nuclei were stained with DAPI. Images were captured on the DAPI and Texas Red channels and a composite overlay image was made (A) (white bar represents 100μm). Male mice with established TRAMP-C2 tumors were treated with Ad-BHG: MG1-GFP (n = 8), Ad-STEAP: MG1-STEAP (n = 16) and compared to a control group of untreated mice (n = 18) (data combined from 2 experiments). Tumor volumes are plotted for each group from a single experiment (B) (arrows denote timings of MG1 treatments, mean and SEM displayed) and tumor volume fold change was calculated for all mice (mean fold change of tumor volume and SEM displayed, comparison performed using ANOVA, **p ≤ 0.01, ***p ≤ 0.001) and collective median survival times were calculated from the initiation of treatment (C) (log rank test used to compare survival times, ****p ≤ 0.0001). ICS on peripheral blood cells following re-stimulation with pooled murine STEAP peptides was performed at the time of peak-boost responses (E) (mean and SEM displayed, comparison performed using ANOVA, ****p ≤ 0.0001).