Array-comparative Genomic Hybridization Analysis of Alveolar Soft Part Sarcoma

Background : Alveolar soft part sarcomas (ASPSs) are rare, histologically distinctive soft tissue sarcomas of unknown origin. Although ASPSs are characterized by a specific alteration, der(17)t(X;17)(p11;q25), the entire spectrum of genetic events underlying the pathogenesis of ASPS is unclear. Using array-based comparative genomic hybridization (array-CGH), we examined the DNA copy number changes in ASPS. Methods : Array-CGH, composed of 4,030 clones, was performed in two samples of fresh frozen tumor tissues from a 29-year-old male and a 16-year-old female. Results : We identified 16 commonly altered chromosomal regions involving 25 genes. Eleven altered regions were located on chromosome Xp (Xp22.33, Xp22.11, Xp11.3, Xp11.3-Xp11.23, Xp22.2, Xp22.12, Xp22.31, Xp22.32, Xp21.1, Xp21.3, and Xp11.4). Additional regions with an increased copy number were observed at 1q25.1, 7q35, 12p12.1, and 17p11.2. Loss was found in only one region of chromosome 22q11.23. Several genes located within the amplified region of Xp included GYG2, ARSD, ARSE, ARSH, UBE1, USP11, PCTK1, ARAF SYN1, TIMP1, XK, PDK3, PCYT1B, PHEX, ARK, RPS6KA3, TMSB4X, TMEM27, BMX, and KAL1. Conclusions: This was the first application report of genome-wide copy number changes by BAC array-CGH in ASPSs. Our study showed unique genomic regions and new candidate genes that suggest a neural origin and are associated with tumor pathogenesis in ASPSs.