title: Interphase cytogenetic analysis of distinct X-chromosomal translocation breakpoints in synovial sarcoma.
abstract: Synovial sarcomas show a specific translocation involving chromosomes X and 18, t(X;18)(p11.2;q11.2). Two distinct X-chromosomal breakpoints occur in different synovial sarcoma tumour samples. These breakpoints are located within two related genomic regions containing ornithine aminotransferase-like sequences, termed OATL1 and OATL2. Preliminary observations indicated the potential correlation of OATL1-associated breakpoints with biphasic tumours and OATL2-associated breakpoints with monophasic fibrous tumours. The present study uses interphase cytogenetics to investigate the nature of chromosomal aberrations in frozen synovial sarcoma tissue samples. Two-colour fluorescence in situ hybridization (FISH) was performed using probes specific for the centromeres of chromosome X or 18, along with yeast artificial chromosome probes corresponding to the distinct breakpoint regions on Xp. One monophasic epithelial and two monophasic fibrous synovial sarcomas showed an OATL2-associated breakpoint, while a biphasic tumour revealed a hybridization pattern indicating a breakpoint within the OATL1 region. These results confirm our previous suggestion of a relationship between alternative breakpoints in Xp11.2 and different histological phenotypes observed in synovial sarcomas. They also demonstrate the utility of the two-colour hybridization approach for the identification of chromosomal changes in interphase nuclei isolated from frozen tissues.
authors.affiliation: Institute for Molecular Biology, Hannover Medical School, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Janz
authors.forename: B
authors.initials: B
authors.lastname: De Leeuw
authors.forename: D O
authors.initials: DO
authors.lastname: Weghuis
authors.forename: M
authors.initials: M
authors.lastname: Werner
authors.forename: M
authors.initials: M
authors.lastname: Nolte
authors.forename: A
authors.initials: A
authors.lastname: Geurts Van Kessel
authors.forename: A
authors.initials: A
authors.lastname: Nordheim
authors.forename: R A
authors.initials: RA
authors.lastname: Hipskind
mesh_terms: D002887:Chromosomes, Human, Pair 18; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D013584:Sarcoma, Synovial / Q000235:genetics* / Q000378:metabolism; D014178:Translocation, Genetic; D014960:X Chromosome