Continuous high-resolutionin vivoimaging reveals tumor-specific dissemination in an embryonic zebrafish xenograft model

Abstract

Mechanisms mediating tumor metastasis are crucial for diagnostic and therapeutic targeting. Here, we take advantage of a transparent embryonic zebrafish xenograft model (eZXM) to visualize and track injected human leukemic and breast cancer cells in real time using selective plane illumination microscopy (SPIM) for up to 30 hours. Injected cells exhibited disease-specific patterns of intravascular distribution with leukemic cells moving faster than breast cancer cells. While breast cancer cells predominantly adhered to nearby regions, about 30% invaded the avascularized tissue, reminiscent of their metastatic phenotype. Survival of the injected tumor cells was partly inhibited by the cellular innate immune system of the recipient embryos and leukemic cell dissemination was effectively inhibited by pharmacological ROCK1 blockade. These observations, and the ability to image several embryos simultaneously, support the use of eZXM and SPIM imaging as a functional screening platform to identify compounds that restricts cancer cell spread and invasion.

Preclinical evaluation of platinum-loaded hydroxyapatite nanoparticles in an embryonic zebrafish xenograft model

“…In our previous study, we utilized high resolution selective plane illumination microscopy (SPIM) to characterize in detail, the dissemination behavior of injected human breast cancer cells in vivo. 23 Also, SPIM imaging allowed us to monitor the cells in real time with high spatial and temporal resolution, thereby analyzing the cancer cell behavior, migration pattern, extravasation and invasion of tumor cells into the zebrafish embryos. Also 80% of the injected cells retained inside the larvae until 3 dpi, provided sufficient window for the drug screening.…”

“…Moreover, we have validated the model for anti-leukemic drug and other studies have shown a pre-treatment drug sensitivity platform for patientderived multiple myeloma and breast tumor cells in zebrafish xenografts. 23,30,48,49 In the current study, we have utilized the previously characterized breast metastatic zebrafish embryonic xenografts for testing the efficacy of PtPP-loaded HA nanoparticles as local drug carriers. Previous studies described that zebrafish embryos can be employed to test the toxic effects of HA nanoparticles with different shapes, albeit in an indirect manner.…”

“…Previously characterized embryonic zebrafish xenograft model from our group was utilized to evaluate the in vivo efficacy of PtPP on breast cancer cells (MDA-MB-231_eGFP). 23 Upon injection of breast cancer cells at the Duct of Cuvier, cancer cells migrated via the blood throughout the embryo as observed by fluorescent microscopy while few cancer cells exhibited extravasation by forming huge protrusions near the vessel wall thereby migrating towards the avascular region (Fig. S3 †).…”

“…21 In view of this, zebrafish models have been advocated recently as an alternative model to study tumor development, tumor progression, metastasis, and drug screening. [22][23][24][25][26][27][28][29][30][31] Zebrafish embryos are also increasingly used to explore the toxic and phenotypic effects of nanoparticles for their application in biomedicine. [32][33][34] However, zebrafish embryos have not been used for direct evaluation of the therapeutic efficacy of drugloaded HA nanoparticles.…”

Multi-sample SPIM image acquisition, processing and analysis of vascular growth in zebrafish

“…Examples include patient-derived samples, xenotransplantation samples, observations of induced cancer cells or small-scale screens of selected compounds. Our multi-sample platform has already been applied successfully to such a study where the influence of the Rho-kinase inhibitor fasudil was investigated on drug-treated and non-drug-treated fish in the same experiment (Asokan et al, 2017preprint). In future, the platform will provide the required sample capacity to tackle more such projects.…”