Fig. 8: PAX7 dictates rhabdomyosarcoma identity in ASP^cKO tumors.

a Representative transmission electron micrograph of an ASP^cKOP7^cKO tumor (n = 3) showing hallmarks of LMS; arrowhead = grooved nuclei, and arrow = prominent rough endoplasmic reticulum. Scale bar = 1 μm. b Representative histology of smooth-muscle differentiated tumor markers SMA and CALDESMON in ASP^cKOP7^cKO (n = 14), ASP^cKO (n = 4), and ASP^WT (n = 4) tumors. Scale bar, 25 μm. c, d Principal component analysis (c) and a volcano plot (d) of top 3000 differentially expressed genes (for c) and the significantly different (P < 0.05) and fourfold differentially expressed genes between the flow cytometry-sorted ASP^cKO and ASP^cKOP7^cKO tumor cells (d). Data represented as the log2 fold change of ASP^cKO/ASP^cKOP7^cKO. Gold indicates the 1002 genes enriched in the ASP^cKOP7^cKO tumor cells. Blue indicates the 973 genes enriched in the ASP^cKO tumor cells. Complete RNAseq data shown in Supplementary Data 3. P values calculated by two-tailed unpaired t test in limma package. e Heatmap of selected significantly (P < 0.05) differentially expressed genes (>fourfold, mean centered per gene) between tdTomato⁺/CD31⁻ tumor cell populations from ASTP^cKO and ASTP^cKOP7^cKO tumors, n = 4 tumors per genotype. f, g GO analysis of differentially expressed genes (up in ASP^cKO, (f)) (up in ASP^cKOP7^cKO, (g)) between flow cytometry-sorted tumor populations from both genotypes; top ten unique GO terms depicted following DAVID functional annotation clustering. h Normalized enrichment scores of gene sets enriched ASP^cKO tumors compared to ASP^cKOP7^cKO tumors according to Gene Set Enrichment Analysis (GSEA). Dark blue = enriched in ASP^cKO and light blue = enriched in ASP^cKOP7^cKO. i, j Enrichment plots of skeletal myogenic (i, Reactome, myogenesis) and smooth muscle (j, Reactome, smooth-muscle contraction) gene signatures from (h). See also Supplementary Fig. 8 and Supplementary Data 3. Source data are provided as a Source Data file.