Figure 7

kdr downstream of TP53^P153Δ predisposes to head embryonal rhabdomyosarcoma (ERMS) in tp53-/- zebrafish.

(A) Volcano plot comparing head to trunk ERMS tumors. Genes with adj. p-value<0.01 and fold-change >2 are colored in red (upregulated in head tumor) or blue (downregulated in head tumor). Table adjacent the plot shows the top differentially expressed genes. (B) Western blot showing p53, KDR, and RUNX2 protein expression in bone marrow mesenchymal cells, the osteosarcoma PDX expressing TP53P153Δ, and osteosarcoma cell lines SaOS2 and 143B. (C) Representative KDR IHC staining of osteosarcoma PDX expressing p53P153Δ. Scale bar = 60 µm. (E) Schematic demonstrating microinjection into the one-cell-stage zebrafish embryos with the indicated constructs to generate GFP-expressing tumors with either kdr or mitfa mosaically deleted in vivo. (F) Kaplan–Meier plot showing ERMS tumor initiation in tp53-/- fish expression TP53P153Δ with either mitfa or kdr ablation. (H) Representative H&E staining of tumors in tp53-/- fish or tp53-/- fish expressingTP53P153Δ with either mitfa or kdr ablation. Scale bar = 60 µm (G) Representative images of tumor localization in tp53-/- fish with expression of TP53P153Δ with either mitfa or kdr deletion. Fish in the panels are 30 days old. (I) Pie chart showing the percentage of tumors found in varying regions of tp53-/- fish with expression of TP53P153Δ with either mitfa or kdr deletion, showing significant differences in the head region. *p=0.0088 (two-tailed two proportions Z-test). (J) Example of sequencing from an ERMS tumor with a deletion in a portion of kdr exon 13. Five of five of ERMS tumors analyzed have deletions in kdr.