A Novel Xenograft Model in Zebrafish for High-Resolution Investigating Dynamics of Neovascularization in Tumors

Abstract

Tumor neovascularization is a highly complex process including multiple steps. Understanding this process, especially the initial stage, has been limited by the difficulties of real-time visualizing the neovascularization embedded in tumor tissues in living animal models. In the present study, we have established a xenograft model in zebrafish by implanting mammalian tumor cells into the perivitelline space of 48 hours old Tg(Flk1:EGFP) transgenic zebrafish embryos. With this model, we dynamically visualized the process of tumor neovascularization, with unprecedented high-resolution, including new sprouts from the host vessels and the origination from VEGFR2+ individual endothelial cells. Moreover, we quantified their contributions during the formation of vascular network in tumor. Real-time observations revealed that angiogenic sprouts in tumors preferred to connect each other to form endothelial loops, and more and more endothelial loops accumulated into the irregular and chaotic vascular network. The over-expression of VEGF165 in tumor cells significantly affected the vascularization in xenografts, not only the number and size of neo-vessels but the abnormalities of tumor vascular architecture. The specific inhibitor of VEGFR2, SU5416, significantly inhibited the vascularization and the growth of melanoma xenografts, but had little affects to normal vessels in zebrafish. Thus, this zebrafish/tumor xenograft model not only provides a unique window to investigate the earliest events of tumoral neoangiogenesis, but is sensitive to be used as an experimental platform to rapidly and visually evaluate functions of angiogenic-related genes. Finally, it also offers an efficient and cost-effective means for the rapid evaluation of anti-angiogenic chemicals.

Preclinical Evaluation of a Novel Orally Available SRC/Raf/VEGFR2 Inhibitor, SKLB646, in the Treatment of Triple-Negative Breast Cancer

“…The cell suspensions were implanted into each zebrafish embryo to create a tumor xenograft model in zebrafish (26). One day after implantation, SKLB646 and dasatinib were added directly into the fish water at different final concentrations.…”

“…A tumor-induced neovascularization zebrafish model was further conducted to evaluate the effect of SKLB646 on angiogenesis in vivo (26). In the control group, endothelial cells were found to penetrate into the tumor tissue by two days after the implantation of tumor cells in zebrafish embryos, hence sustaining the tumor growth.…”

The Study of Glioma by Xenotransplantation in Zebrafish Early Life Stages

“…In some studies, some cancer cell lines are able to tolerate 28°C Zhao et al 2009Zhao et al , 2011a. For the GBM cell line, U251, it has been demonstrated that varying the incubation temperature between 28°C and 35°C has no effect on the survival of cells after engraftment (Geiger et al, 2008).…”

A Preclinical Evaluation of SKLB261, a Multikinase Inhibitor of EGFR/Src/VEGFR2, as a Therapeutic Agent against Pancreatic Cancer

“…We then used a tumor xenograft model in zebrafish, which was reported previously (34), to further evaluate the antiangiogenic effect of SKLB261. Briefly, red fluorescence-labeled B16 tumor cells were implanted into 48 hours postfertilization (hpf) embryos through the perivitelline space.…”