Efficacy test in zebrafish of Folfox and Folfiri against HCT116 cells.

Zebrafish larvae xenografts as been presented as a wonderful tool that has been widely used in cancer research.

This zebrafish avatar model as been developed to study the response of specific cancers to several anti-cancer therapies. In order to discriminate between 2 treatments currently used for Colon rectal cancer (CRC) chemotherapy, zebrafish larvae were injected at 2 days post fertilization (dpf) with the CRC stable cell line HCT116_GFP+ at perivitelline space (PVS).

In the following image, it is shown zebrafish larvae injected at 1 day post injection (dpi) representing a control and respective treatments Folfox and Folfiri at the time that the drugs were added.

In the next panel the same fish at the end point of the experiment (4dpi). As can be observed the tumor size of Folfiri-treated embryos is smaller than the control ones. In order to quantify the tumor between control and treated fish, an immunofluorescent (IF) protocol were performed. (B) SiR was used to label the nuclei (red), caspase3 (casp3) as a marker for cell death (green) and Histone H3 (HH3) as a cellular division marker (green). The number of cell nuclei together with the number of positive cells for caspase3 and HH3 for each condition were counted using the ImageJ software and the data plot into a graph. The data presented shown that a reduction in the tumor size can be observed when using Folfox and Folfiri being Folfiri more effective. Also, a decrease in cellular division and an increase of cell death can be observed in the treated tumors what correspond to the reduction of tumor observed. n=40 fish analyzed for nuclei number per condition, n=20 fish analyzed for casp3 and HH3 positive cells per condition,  *P < 0.05; **P < 0.005; ***P < 0.0001;****P<0.00001 ns, nonsignificant.