K5 camera

Images were acquired using a fluorescent stereoscope (Leica) equipped with a K5 camera (Leica) with resolution (h x v) 2048 × 2048 pixels and pixel size (h x v) 6.5 × 6.5 μm, at an image magnification of 100x with no binning. Images were obtained right after implantation (0 days post injection, dpi) and after 72 h incubation (3 dpi) and analyzed by using the HuginMunin software v2.7.0.0 (BioReperia AB, Linköping, Sweden). Tumor sizes were analyzed as the area of labeled tumor cells at 0 dpi and 3 dpi, and the number of disseminated cells to the caudal venous plexus were manually counted. Relative tumor size was calculated by dividing the tumor area at 3 dpi by the area at 0 dpi in the same embryo and multiply by 100.

zCDX models were developed by a CRO (BioReperia AB). Transgenic Tg(fli1:EGFP)y1 zebrafish embryos were raised at 28 °C for 48 h in E3 embryo medium (containing per liter: 0.286 g NaCl, 0.048 g CaCl2, 0.081 g MgSO4 and 0.0126 g KCl with 0.2 mM 1-Phenyl-2-Thiourea aka PTU). At 2 days post-fertilization, embryos were injected subcutaneously in the perivitelline space with transfected parental and CDDP-R cells previously labeled with FAST Dil™ oil (Thermo Fisher Scientific) and treated with ± Cisplatin 5 mg/L for 3 days. Images of tumors were taken by using a fluorescent stereoscope with a K5 camera (Leica) and LAS X software v3.7.1.21655 at 100×  magnification with no binning. Images of tumors were taken right after injection (day 1) and after drug treatment (day 4). Images were automatically analyzed by using the HuginMunin software v2.7.0.0 (BioReperia AB). Tumor growth regression was calculated by dividing the number of tumor pixels on day 4 by the number of tumor pixels on day 1 in the same embryo and multiplied by 100.

All brightfield images were taken using a Leica Aperio LSM^™ slide scanner under 20X objective. All immunofluorescent images were taken on the Leica Thunder imager DMi8. Images were acquired at 20x using a Leica K5 camera. Leica biosystems LAS X software was used for image capture. Tiles covering the entire ION were taken and stitched. Leica Thunder instant computational clearing was used to remove out of focus light. The images were exported as tiff files for downstream analysis.