RNA-Seq of Primary and Recurrent DSRCT Tumors

Desmoplastic small round cell tumor (DSRCT) is a rare pediatric cancer caused by the EWSR1-WT1 fusion oncogene. Despite initial response to chemotherapy, DSRCT has a recurrence rate of over 80% leading to poor patient prognosis with a 5-year survival rate of only 15-25%. Owing to the rarity of DSRCT, sample scarcity is a barrier to understanding DSRCT biology and developing effective therapies. Here, we performed RNA-sequencing on a novel pair of primary and recurrent DSRCT tumors harvested from the same patient 5-years apart. To gain insights into gene expression alterations associated with recurrence, we performed pathway analysis on Gene Ontology Biological Processes and KEGG pathways. Upregulated pathways in the recurrent tumor included DNA repair and mRNA splicing related pathways, while downregulated pathways included immune system function and focal adhesion. We further examined the expression of previously identified EWSR1-WT1 regulated targets, a large number of which were enriched in the recurrent tumor. Overall, this study provides novel understanding of DSRCT biology and a new RNA-seq data set to advance future studies. Overall design: RNA sequencing was performed on a set of primary and recurrent DSRCT samples from the same patient. Gene expression and pathway alterations were examined