title: Recurrent and novel SS18-SSX fusion transcripts in synovial sarcoma: description of three new cases.
abstract: Synovial sarcoma (SS) is an aggressive type of tumor, comprising approximately 10 % of soft tissue sarcomas. Over 90 % of SS cases are characterized by the t(X;18)(p11.2;q11.2) translocation, which results mainly in the formation of oncogenic SS18-SSX1 or SS18-SSX2 fusions. In a typical SS18-SSX fusion transcript, exon 10 of SS18 is fused to exon 6 of SSX1/2. However, several variant fusion transcripts have been already described. In the present study, we examined the fusion transcript type in a series of 40 primary untreated SS tumor specimens using reverse transcription polymerase chain reaction and fluorescence in situ hybridization assay. We detected SS18-SSX1 transcript in 22 (55 %) patients and SS18-SSX2 transcript in 17 (42.5 %) patients, while in one patient, none of SS18-SSX1/2 fusion transcripts were identified. Among the cases under study, two tumors carried novel SS18-SSX1 and SS18-SSX2 variant translocations that were allegedly created by an alternative splicing, and in additional case, an unusual translocation variant previously described by other group was found. Our data suggest that alternative splicing may play an important role in novel fusion transcript formation, and additionally we show that it may be a recurrent event in SS. Furthermore, we describe the first case of a complex rearrangement possibly linking SS to REPS2 gene.
authors.affiliation: Department of Molecular Biology, The Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, 5 WK Roentgen Street, 02-781 Warsaw, Poland. joanna.przybyl@coi.pl
authors.forename: Joanna
authors.initials: J
authors.lastname: Przybyl
authors.forename: Raf
authors.initials: R
authors.lastname: Sciot
authors.forename: Piotr
authors.initials: P
authors.lastname: Rutkowski
authors.forename: Janusz A
authors.initials: JA
authors.lastname: Siedlecki
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vanspauwen
authors.forename: Ignace
authors.initials: I
authors.lastname: Samson
authors.forename: Maria
authors.initials: M
authors.lastname: Debiec-Rychter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000235:genetics*; D002135:Calcium-Binding Proteins; D002675:Child, Preschool; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D015514:Oncogene Proteins, Fusion; C489722:REPS2 protein, human; D012333:RNA, Messenger; C116512:SYT-SSX fusion protein