Mohseny, A.B., Xiao, W., Carvalho, R., Spaink, H.P., Hogendoorn, P.C., and Cleton-Jansen, AM. (2012) An osteosarcoma zebrafish model implicates Mmp-19 and Ets-1 as well as reduced host immune response in angiogenesis and migration. The Journal of pathology. 227(2):245-253.
About 40% of osteosarcoma patients die of metastases. Novel strategies to improve treatment of metastatic patients require a better understanding of the processes involved, like angiogenesis, migration and the immune response. However the rarity of osteosarcoma and its heterogeneity make this neoplasm difficult to study. Recently we reported malignant transformation of mouse mesenchymal stem cells (MSCs) which formed osteosarcoma upon transplantation into mice. Here we studied these cells in zebrafish embryos and found that transformed MSCs induced angiogenesis and migrated through the bodies of the embryos, but this was never observed with non-transformed normal MSCs (progenitors of the transformed MSCs). Whole genomic expression analysis of both the cells and the host showed that angiogenesis and migration related genes matrix metalloproteinase 19 (Mmp-19) and erythroblastosis virus E26 oncogene homologue 1 (Ets-1) were over-expressed in transformed MSCs compared to normal MSCs. Investigating the host response, embryos injected with transformed MSCs showed decreased expression of immune related genes, especially major histocompatibility complexclass 1 (mhc1ze), as compared to embryos injected with normal MSCs. These findings contribute to the identification of genetic events involved in angiogenesis, migration and host response providing targets as well as an appropriate model for high-throughput drug screens.