Clinicopathologic and molecular analysis of a BCOR–CCNB3 undifferentiated sarcoma of the kidney reveals significant epigenetic alterations

Abstract

Undifferentiated soft tissue sarcomas (UDSTS ) are a group of mesenchymal tumors that remain a diagnostic challenge due to their morphologic heterogeneity and unclear histologic origin (Peters et al. 2015b). In this case report, we present the first multi-omics molecular signature for a BCOR-CCNB3 sarcoma (BCS) that includes mutation analysis, gene expression, DNA methylation, and mi-RNA expression. We identify a paucity of additional mutations in this tumor and detail that there is significant dysregulation of gene expression of epigeneic remodeling agents including key members of the PRC, Sin3A/3b, NuRD, and NcoR/SMRT complexes and the DNA methyltransferases DNMT1, DNMT3a, and DNMT3b. This is accompanied by significant DNA methylation changes and dysregulation of multiple miRNA with known links to tumorigenesis. This study significantly increases our understanding of the BCOR effects on fusion positive undifferentiated sarcomas at both the genomic and epigenomic level and suggests that as better-tailored and more refined treatment algorithms continue to evolve, epigenetic modifying agents should be further evaluated for their efficacy against these tumors.