ZeEfficacy – Efficacy Services

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Tumor xenograft model

The xenograft of human cancer cells in model animals is a powerful tool for understanding tumor progression and metastatic potential. Mice represent a validated host, but their use is limited by the elevated experimental costs and low throughput. To overcome these restrictions, zebrafish larvae might represent a valuable alternative. Interestingly, xenotransplant models in zebrafish have the potential to be used in personalized medicine.

Many of the mechanisms of tumor production are shared by zebrafish and humans:

Our model lies in the injection of fluorescent immortalized human tumor cells in zebrafish embryos. The small size and transparency of zebrafish larvae allow the tracking of transplanted cells in vivo across the body with high resolution and thus, primary tumor growth and early steps of metastasis can be addressed.

Applications

  • Study of genes involved in tumor progression and metastasis processes.
  • Compare the capabilities of different stable cancer cell lines to engraft in zebrafish.
  • Screening of compounds with potential anti-tumoral efficacy, including anti-proliferative, pro-apoptotic, anti-metastatic, and anti-angiogenic.

Advantages

Biologically-relevant readouts: tumor-related genes and signalling pathways are conserved in zebrafish.

High throughput screening: automated measurements of initial proliferation and metastatic events.

Few cells and drug amounts needed.

NO need for immuno-compromised animals.

Direct in vivo observation in transparent embryos.

High sensitivity: possibility to look at micrometastasis.

Real volumen observed, not estimated as with confocal.

Method description

Immortalized tumor cells are cultured and transfected with a fluorescent protein before injection in the perivitelline space of early-life embryos (2 dpf). Individualized larvae are imaged at time point 1 shortly after being injected, and then they are treated with the compounds of interest for up to 4 days. Finally, embryos are imaged at time point 2 in order to analyze the effect of drugs on tumor progression and initial metastasis.

High-resolution imaging of zebrafish larvae through VAST bioimager allows high throughput screening and 3D images in real time. 96 larvae are individually placed in a glass capillary and rotated in an automatic manner for imaging in a short time.

Readouts

  • Tumor progressión: ratio of tumor volume of each individualized larva at time point 2/time point 1.
  • Metastatic events: number and dispersion of the micrometastasis, and distance to the primary tumor.
Figure 2. Tumor progression evaluation. A) High-resolution imaging of a zebrafish larva shortly after the xenotransplantations (timepoint 1), and the same larva after few days of vehicle (DMSO) treatment (timepoint 2). B) Quantification of tumor progression as the ratio of tumor volume at timepoint 2 divided by tumor volume at timepoint 1.