TFG is a novel fusion partner of NORI in extraskeletal myxoid chondrosarcoma

Extraskeletal myxoid chondrosarcoma (EMC) is characterized by recurrent chromosomal translocations resulting in fusions of the nuclear receptor gene NOR1 (also known as CHN or TEC) to various N-terminal partners, including EWS and TAF2N (or RBP56). Significant structural homology of EWS or TAF2N to TLS (or FUS) prompted us to investigate a potential novel gene fusion of NOR1 to TLS in EMCs without detectable known NOR1 fusions. In one of the EMCs examined, our reverse-transcription polymerase chain reaction using NOR1 and TLS primers unexpectedly amplified a cDNA sequence derived not from a TLS/NOR1 fusion but from a TFG/NOR1 fusion, a hitherto undescribed fusion type in EMC, probably a result of incidental misannealing by the TLS primer, which has a sequence partially identical to TFG. Encoding a protein with a putative coiled-coil structure, TFG previously was identified by a homology search in the Expressed Sequence Tag Database as having an SPYGQ-rich region similar to the N-terminal parts of EWS and TLS. TFG/NOR1 fusion appears to play an oncogenic role equivalent to those of other NOR1 fusions in EMC. (C) 2004 Wiley-Liss, Inc.