Figure 4

Figure 4

CAR NK-92 cells specific for PD-L1 or ErbB2 show high efficacy against resistant breast cancer cells in a zebrafish xenograft model. (A) Zebrafish larvae were injected at 2 dpf with MDA-MB-231 GFP cells and 2.5 hours later with PKH26-labeled PD-L1.CAR NK-92 or parental NK-92 cells. For each cell type an average 100 cells was injected. Images were captured by fluorescence microscopy at time points of 48 hpi. Scale bar = 250 μm. (B) The number of MDA-MB-231 GFP cells was quantified at 48 hpi. Data are pooled from 6 independent experiments and shown as mean ± SD. n=41 (MDA-MB-231 GFP), n=19 (MDA-MB-231 GFP+NK-92), n=31 (MDA-MB-231 GFP+PD-L1.CAR NK-92). (C) Schematic representation of ErbB2-specific CAR NK-92 (ErbB2.CAR NK-92) targeting ErbB2+ MDA-MB-453 metastatic breast cancer cell line. Illustration created with BioRender. (D) Zebrafish larvae were injected at 2 dpf with MDA-MB-453 GFP cells and 2.5 hours later with PKH26-labeled ErbB2.CAR NK-92 or parental NK-92 cells. For each cell type, 100 cells were injected on average. Images were captured by fluorescence microscopy at 8 hpi and the number of cancer cells was quantified. Data were pooled from 2 independent experiments and means ± SD are shown. n=8 (MDA-MB-453 GFP) n=13 (MDA-MB-453 GFP+NK-92), n=14 (MDA-MB-453 GFP+ErbB2.CAR NK-92). One-way ANOVA analysis with Tukey’s multiple comparison was used for statistical analysis. *p=0.0154. **P<0.01; ***P<0.001; ****P<0.0001.