Fig. 3

CRC xenografts show different sensitivities to standard chemotherapy. Human CRC zebrafish xenografts were treated in vivo with FOLFOX (F–J) and FOLFIRI (K–O) compared with nontreated controls (A–E). Zebrafish were killed and fixed at 4 dpi, 3 days posttreatment (3 dpT). Mitotic index (P) (DAPI in blue) and cell death by apoptosis (Q) (activated caspase3 in green) were analyzed and quantified. Average tumor size (number of DAPI cells), normalized to respective controls, was also quantified to compare between different xenografts in different conditions (R). All pictures are at the same magnification (A–O). Results in P–R are expressed as AVG ± SEM. Results are averages from at least three independent experiments, and the total number of xenografts analyzed is indicated in the images; ns, nonsignificant; P values are indicated in the text, ***P < 0.001. HCT116 and Hke3 polyclonal xenografts (1:1) were generated and randomly treated with FOLFIRI (T) and compared with untreated controls (S). Xenografts were fixed at 4 dpi, 3 dpT. The percentages of each clone (U), cell death by apoptosis (V) (activated caspase3), mitotic index (W), and the size of each clone per xenograft (X), were analyzed and quantified. Each dot represents a xenograft, Hke3_caspase3 **P = 0.041, Hke3_mitosis **P = 0.006, remaining P values are indicated in the text, and *P < 0.05; **P < 0.005; ***P < 0.001. The total number of xenografts analyzed is indicated in the images. HCT116 was labeled with DiI (red) and Hke3 with DeepRed (green, false color).