Figure 2. RNA sequencing and experimental validation of a novel FOS-LMNA gene fusion in a typical EH of bone (case#1).
(A) Schematic representation of RNA sequencing indicating the LMNA locus joined with the FOS gene, resulting in a t(1;14)(q22;q24.3) translocation. (B) RT-PCR confirmed both the FOS-LMNA and the reciprocal LMNA-FOS chimeric transcript. (C) FISH assay validated break-apart signals in both FOS and LMNA genes. (D) Normalized RNA sequencing read per kilobase per million mapped reads (RPKM) showed significant FOS mRNA upregulation in the index case (FOS-positive EH1), FOSB-rearranged cases (FOSB-positive EHa & EHb), and a fusion-negative EH (EHc), compared to epithelioid hemangioendothelioma (EHE), angiosarcoma (AS), and glomus tumor (G).