Affymetrix SNP array data for soft tissue sarcoma samples

Soft tissue sarcomas are aggressive mesenchymal cancers that affect more than 10,600 new patients per year in the US, about 40% of whom will die of their disease. Soft tissue sarcomas exhibit remarkable histologic diversity, with more than 50 recognized subtypes, but our knowledge of their genomic alterations is limited. Here we describe the results of an integrative analysis of DNA sequence, copy number, and mRNA expression in 207 samples encompassing seven major subtypes. Genes mutated in more than 5% of samples within a subtype were KIT (in gastrointestinal stromal cell tumors, or GISTs), TP53 (pleomorphic liposarcomas), PIK3CA (myxoid/round-cell liposarcoma), and NF1 (both myxofibrosarcoma and pleomorphic liposarcoma). We show evidence that PIK3CA mutations, found in 18% of myxoid/round-cell liposarcomas, activate AKT in vivo and are associated with poor outcomes. Point mutations in the tumor suppressor gene NF1 were discovered in both myxofibrosarcomas and pleomorphic liposarcomas, while genomic deletions were observed in all subtypes at varying frequencies. Finally, we found that short hairpin RNA-based knockdown of a subset of genes that are amplified in dedifferentiated liposarcoma, including CDK4 and YEATS4, decreased cell proliferation. Our study yields the most detailed map of molecular alterations across diverse sarcoma subtypes to date and provides potential subtype-specific targets for therapy.