The CHOP Breakapart probe consists of a green 165kb probe and a red 146kb probe, which are positioned on each side of the CHOP (DDIT3) gene.
Myxoid liposarcoma (MLS) is the most common subtype of liposarcoma1. The TLS-CHOP (FUS-DDIT3) t(12;16)(q13.3;p11) fusion gene, firstly described by Turc-Carel et al. in 19862, is now well established and is present in at least 95% of MLS3.
In rare cases, an EWS-CHOP (EWSR1-DDIT3) t(12;22)(q13;q12) translocation has been described4. The transcription factor gene, CHOP (DDIT3) (CREBP-homologous protein/DNA damage inducible transcript 3), is a negative regulator of adipocyte differentiation5.
The TLS (Translocated in Liposarcoma)6 or FUS7 gene is a nuclear RNA-binding protein with extensive sequence similarity to EWS. The TLS-CHOP protein interferes with adipocyte differentiation and favours proliferation over terminal differentiation4.
It was very important for us to have more consistent results with our probes — easy-to-read bright signals and a range of vial sizes, which is much more cost-effective. It also was critical to upgrade our pretreatment kit to expedite the analysis of FFPE samples. We can now complete the process in about 90 minutes.
Janet Cowan, PhD
Director of the Cytogenetics Laboratory, Tufts Medical Center, USA