Expression profiling of Ewing sarcoma samples in the frame of the CIT program from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net). Ewing sarcoma a rare pediatric tumor characterized by EWSR1-ETS fusions, is predominantly observed in populations of European ancestry. A genome-wide association study of at least 401 French ES patients compared to either 684 French or 3668 US self-described Caucasian controls consistently revealed candidate loci at chromosomes 1 and 10 (p<10-6). These loci were further replicated in two independent sets of cases and controls. Joint analysis identified rs9430161 (p=1.4x10-20; OR=2.2, CI99=1.8-2.7) 25kb upstream to TARDBP (1p36.22) and rs224278 (p=4.0x10-17 OR=1.7, CI99=1.4-1.9) 5kb upstream to EGR2 (10q21). The frequency of the major risk haplotypes in the European population were observed to be less prevalent in the African population, suggesting that variants at these loci could contribute to the differences in ES incidence observed between continents. TARDBP shares structural similarities with EWSR1 and FUS (TLS) EGR2 is an EWSR1-ETS target gene. Variants at both loci were associated with expression levels of TARDBP, ADO and EGR2.
Overall design
117 Ewing sarcoma samples were profiled using affymetrix hgu133Plus2 arrays.