Fig. 6: Genes expressed within the melanoma with rhabdomyosarcomatous transdifferentiation (PR42800).

H&E (a) and desmin immunohistochemistry (b) of melanoma with rhabdomyosarcomatous transdifferentiation. The conventional melanoma is marked by a red asterisk, rhabdomyosarcomatous transdifferentiation by a green asterisk, and normal adjacent skeletal muscle by a blue asterisk. Expression of key skeletal muscle marker genes with transcripts per kilobase million (TPM) determined using DESeq2 (c). Note, the normal tissue was adjacent to normal skeletal muscle as indicated in (a). Importantly, MYOD1 and MYOG RNA are expressed in normal skeletal muscle (i.e., the control tissue) but an expression of these markers at the protein level is absent. Conversely, the presence of MYOD1 and MYOG RNA in the conventional melanoma with no associated protein expression may be explained by contamination from the adjacent (or underlying) normal skeletal muscle. CASZ1 somatic mutation status (d). CASZ1 gene expression has previously been linked to a rhabdomyosarcomatous transdifferentiation program.