A specific translocation in this sarcoma induces fusion of the SYT gene on chromosome 18 to the SSX genes on chromosome X, leading to proliferation of the tumor cells.
As one of the first sarcomas to be defined by the presence of a specific chromosomal translocation leading to the production of the SS18-SSX fusion oncogene, it is perhaps the archetypal "translocation-associated sarcoma," and its translocation remains unique to this tumor type.
These results support the notion that the SYT-SSX2 nuclear function and differentiation effects are conserved throughout sarcoma development and are required for its maintenance beyond the initial phase.
Furthermore, tumors were screened for gene fusions (PAX3-FKHR, ASPL-TFE3, and SYT-SSX) previously shown to be associated with MET activation in sarcomas.
A characteristic SYT-SSX fusion gene resulting from the chromosomal translocation t(X;18)(p11;q11) is detectable in almost all synovial sarcomas, a malignant soft tissue tumor widely believed to originate from as yet unidentified pluripotent stem cells.
Synovial sarcoma is a soft tissue cancer associated with a recurrent t(X:18) translocation event that generates one of two fusion proteins, SYT-SSX1 or SYT-SSX2.
In three types of SSs, monophasic fibrous, biphasic and poorly differentiated, NBT/BCIP signals corresponding to SYT-SSX mRNA were uniformly and predominantly positive in the sarcoma cell cytoplasm.
With this method, 27 tumors (9 synovial sarcomas and 18 nonsynovial sarcomas) were studied and showed SYT-SSX1 rearrangement in 6 cases and SYT-SSX2 in 3 cases.
We attempted to determine the influence of the two alternative forms of the SYT-SSX fusion gene on tumor morphology and clinical outcome in patients with this sarcoma.