Fluorescence in situ hybridization for the detection of t(X;18)(p11.2;q11.2) in a synovial sarcoma tissue microarray using a breakapart-style probe.
Synovial sarcomas (SSs) account for 5% of soft tissue tumors and carry a balanced translocation t(X;18)(p11.2;q11.2), detectable in over 90% of cases. This translocation brings together portions of two genes: SYT and SSX. Detecting interruption of the SYT gene on chromosome 18 would be useful as a diagnostic tool. We describe a scoring method to detect disruption of SYT with breakapart probe fluorescence in situ hybridization (FISH) and the application of this method for identification of SS within a sarcoma tissue microarray. After optimization, SYT disruption was identified in 22 of 23 (96%) of known SS tumor samples but was not in 23 of 23 (100%) of non-SS sarcoma samples. Ten of 11 (91%) blinded test SS tumor samples were also correctly identified. For comparison, commercially available FISH and chromogenic in situ hybridization (CISH) probes were tested. The commercial FISH probes identified SYT disruption in 81% of the SS tumor samples but in none of the non-SS samples. The CISH probes produced signals too weak to interpret. The use of breakapart FISH probes is a relatively quick procedure for detection of synovial sarcoma translocations and can be applied to archival specimens in tissue microarrays.
Terry
Jefferson
J
Genetic Pathology Evaluation Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
Barry
Todd S
TS
Horsman
Douglas E
DE
Hsu
Forrest D
FD
Gown
Allen M
AM
Huntsman
David G
DG
Nielsen
Torsten O
TO
D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D015341:Nucleic Acid Probes; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D013584:Sarcoma, Synovial / Q000175:diagnosis* / Q000235:genetics; D017384:Sequence Deletion; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000235:genetics; D046888:Tissue Array Analysis; D014178:Translocation, Genetic
D018076:DNA, Complementary; D015341:Nucleic Acid Probes; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; C093961:SS18 protein, human