Developing a Novel Embryo–Larval Zebrafish Xenograft Assay to Prioritize Human Glioblastoma Therapeutics

Abstract

Glioblastoma is an aggressive brain cancer requiring improved treatments. Existing methods of drug discovery and development require years before new therapeutics become available to patients. Zebrafish xenograft models hold promise for prioritizing drug development. We have developed an embryo-larval zebrafish xenograft assay in which cancer cells are implanted in a brain microenvironment to discover and prioritize compounds that impact glioblastoma proliferation, migration, and invasion. We illustrate the utility of our assay by evaluating the well-studied, phosphatidylinositide 3-kinase inhibitor LY294002 and zinc oxide nanoparticles (ZnO NPs), which demonstrate selective cancer cytotoxicity in cell culture, but the in vivo effectiveness has not been established. Exposures of 3.125-6.25 lM LY294002 significantly decreased proliferation up to 34% with concentration-dependent trends. Exposure to 6.25 lM LY294002 significantly inhibited migration/invasion by *27% within the glioblastoma cell mass (0-80 lm) and by *32% in the next distance region (81-160 lm). Unexpectedly, ZnO enhanced glioblastoma proliferation by *19% and migration/invasion by *35% at the periphery of the cell mass (161+ lm); however, dissolution of these NPs make it difficult to discern whether this was a nano or ionic effect. These results demonstrate that we have a short, relevant, and sensitive zebrafishbased assay to aid glioblastoma therapeutic development.

Identify a Blood-Brain Barrier Penetrating Drug-TNB using Zebrafish Orthotopic Glioblastoma Xenograft Model

“…Furthermore, using this zebrafish tumor model, Wehmas et al . observed significant tumor inhibition effect with exogenous compound (a selective PI3K inhibitor-LY294002) treatment, which was similar to that observed in organotypic mouse brain tissues 18 , 19 . As a model species, zebrafish has numerous strengths, including offspring number, in vitro fertilization and embryo transparency 20 .…”

An orthotopic glioblastoma animal model suitable for high-throughput screenings

“…7,28,29 Orthotopic transplantation procedures of GBM material into embryonic zebrafish have been developed during the last years and their extraordinary disease recapitulating potential described in detail. 10,11,[30][31][32] However, all currently published orthotopic zebrafish models depend on direct intracranial injection, which requires sedation and precise positioning of embryonic zebrafish, and the transplantation process remains slow and technically challenging. Therefore, those Here, we present a substantial improvement of available orthotopic GBM animal models.…”

Fishing for cures: The alLURE of using zebrafish to develop precision oncology therapies

“… Proof of principle for the use of a zebrafish orthotopic xenograft model as a drug screening platform for the treatment of glioblastoma. 60 XT Patient-derived glioma cells Pharmacological test in vivo Currently used glioblastoma therapeutics decrease xenotransplant tumor burden and significantly rescue survival. Validation of a zebrafish orthotopic xenograft model as a drug screening platform for the treatment of glioblastoma.…”

“…The utility of the assay was demonstrated by the ability of a drug with a known anti-cancer effect in cell culture to inhibit proliferation and invasion in the xenograft model. 60 Another study described a platform to study the efficacy of drugs for the treatment of pediatric brain tumors. Mouse ependymoma, glioma, and choroid plexus carcinoma cells were transplanted orthotopically into the brain of zebrafish juveniles.…”