Figure 2. In vivo elimination of suicide gene-engineered stromal cells.
(a) NOD/SCID mice were inoculated with MDA-Luc + CAF-iCasp tumors at mammary fatpads on both flanks, and half of the population was injected with CID homodimerizer at day 10 and 11. Animals were sacrificed on dash-line indicated days and tumor were stained with a human mitochondria-specific antibody. (b) Human mitochondria staining of xenograft tumor sections where MDA/Luc and CAF-iCasp cells were co-implanted into the mammary fatpads of NOD/Scid mice. Fibroblastic human CAF cells remain visible 30 days after implantation in the NTX condition, and hardly seen in the tumors from mice hosts treated with CID injection on day 10 and 11. Scale bar: 100 μm. (c) Morphology-based quantification shows dramatic reduction of human fibroblasts in tumors treated with CID drug (p = 1.4 × 10−5, Student’s t-test). Total images analyzed: NTX: n = 13; CID TX: n = 14. For in vivo study, N = 5 animals per endpoint, per condition. Error bars: standard error of the mean (SEM).