Mutational analysis of PIK3CA, JAK2, BRAF, FOXL2, IDH1, AKT1
and EZH2 oncogenes in sarcomas
Recent studies have revealed several recurrent mutations in oncogenes that could not only be underlying mechanisms of tumorigenesis, but also be potential targets for cancer therapies. Compared to carcinomas, genetic alterations of sarcomas are relatively unknown. To see whether recurrent
oncogenes discovered in non‐sarcomatous malignancies are present in sarcomas as well, we analyzed oncogenes with known mutations in various types of sarcomas. We performed mutational analysis of recurrent mutation sites of PIK3CA (exons 9 and
20), JAK2 (exon 14), BRAF (exon 15), FOXL2 (exon 1), IDH1 (exon 4), AKT1 (exon 3),
and EZH2 (exon 16) genes in 108 sarcomas by single‐ strand conformation polymorphism and DNA sequencing. The sarcomas consisted of malignant fibrous histiocytomas, rhabdomyosarcomas, osteosarcomas, malignant peripheral nerve
sheath tumors, leiomyosarcomas, synovial sarcomas, liposarcomas, angiosarcomas, chondrosarcomas, and Ewing sarcomas. Overall, we detected the two PIK3CA mutations and one JAK2 mutation (total: 3/108: 2.8%).
Two rhabdomyosarcomas (16.7%) and one angiosarcoma (16.7%) harbored the mutations, whereas other sarcomas harbored none. The PIK3CA mutations were novel missense mutations that had not been detected in other cancers. The JAK2
mutation was an intron mutation. This study demonstrated that the somatic mutations of PIK3CA and JAK2 occurred in a small fraction of the sarcomas and that these mutations may not play a principal role in
the development of sarcomas.