Abstract 4177: Dynamic visualization of cancer cell engraftment into immune compromised zebrafish

Abstract

Abstract Cell transplantation into immune compromised mice has transformed our understanding of cancer and is now the gold standard for assessing therapeutic responses in vivo. However, mouse models are expensive and engraftment is often difficult to visualize directly. To overcome these challenges, we have developed immune compromised zebrafish (ICZ) in the transparent casper background using genome editing techniques. We have successfully targeted genes required for immune cell function and are well known to cause immune deficiency in human and mice. To date, we have developed homozygous viable mutants for recombination-activating gene 2 (rag2), DNA-dependent protein kinase (prkdc), janus kinase 3 (jak3), interleukin 2 receptor gamma (Il2rg), zeta-chain (TCR) associated protein kinase 70 (zap70), and forkhead box N1 (foxn1/nude). Gene expression analysis of marrow cells using RNAseq has identified novel transcript changes correlated with loss of specific cell types, and in conjunction with large-scale single cell transcriptional profiling, has identified specific cellular defects associated with T, B, and NK cell loss. For example, homozygous prkdc (SCID) mutant fish lack mature T and B cells, but have intact NK cell signaling. By contrast, il2rg-deficient zebrafish lack T and NK cells. Importantly, these ICZ models accurately recapitulate known human severe combined immune deficiencies and established mouse models that are commonly used for cell transplantation. Thus, it is not unexpected that a subset of zebrafish mutants have reduced immune cell function, permitting engraftment of normal hematopoietic and muscle satellite cells from allogeneic donors. Additionally, we have demonstrated robust and persistent engraftment of fluorescently labeled leukemia, rhabdomyosarcoma, neuroblastoma, and melanoma from a wide range of zebrafish strains. Because mutations have been created in optically-clear, casper-strain zebrafish and cancers are fluorescently labeled, we now have unprecedented access to directly visualize tumor cells at single cell resolution in live animals. To date, we have optimized our models to visualize neovascularization, intratumoral cell heterogeneity, clonal evolution and metastisis. The ability to transplant non-immune matched cell types will likely revolutionize the types and scale of cell transplantation experiments performed in the zebrafish and will likely permit engraftment of mouse and human cells into compound mutant ICZ models in the near future. Citation Format: John C. Moore, Qin Tang, Nora Torres Yordan, Timothy Mulligan, Finola E. Moore, Riadh Lobbardi, Ashwin Ramakrishnan, Anthony Anselmo, Ruslan Sadreyev, Jason Berman, Robert Liwski, Brant Weinstein, John Rawls, David M. Langenau. Dynamic visualization of cancer cell engraftment into immune compromised zebrafish. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4177.