Development of Vestibular Schwannoma Xenograft Zebrafish Model for in Vivo Anti-tumor Drug Screening

Background: The development of a relatively simple, reliant and cost-effective animal test will greatly facilitate drug development. In this study, our goal was the establishment of a rapid, simple, reproducible, and live zebrafish vestibular schwannoma xenograft model for anti-tumor drug screening.

Methods: We optimized the conditions for the tumor cell xenograft in terms of injected cell numbers, stage of larvae, incubation temperature, and incubation time. We used NF2-/- Schwann (SC4) cells. SC4 cells were stained with a mCherry fluorescent protein prior to injection into the zebrafish larvae. SC4 cells were counted by microscopy, suspended in 10% FBS and cells were injected into the center of yolk sac using a micro-injecting system. Injected embryos were transferred to E3 media and subsequent tumor formation was observed under fluorescent microscopy for 5 days. To test our new model, we carried out further validation. Xeno-grafted embryos were transferred in a 6 well plate (5 embryos/well) and treated with several known anti-tumor drugs (RAD001).

Results: MFP-tagged SC4 cells were successfully grafted into the yolk sac of zebrafish embryo without immunosuppressant treatment. 2days after injection, xenografted cell formatted tumor mass. Differences in injected cell numbers, incubation temperature, and larvae stages were reflected in the speed of tumor formation. The preliminary using RAD001 produced > 20% reduction in the SC4 cell number in the yolk.

Conclusion: Our in vivo animal model system should greatly facilitate drug development for acoustic tumor therapy because of its speed, simplicity, reproducibility and live imaging.