[Molecular cytogenetic studies of soft tissue tumors]

Molecular cytogenetic studies of 25 cases of soft tissue tumors, including 8 malignant fibrous histiocytomas (MFH), 13 rhabdomyosarcomas (RMS), 3 Ewing's sarcomas (ES) and 1 synovial sarcoma (SS), were performed. Chromosomal analysis showed that of 17 analyzable cases, 15 had chromosomal numerical and structural abnormalities. In RMS, ES and SS consistent chromosomal abnormalities, t(2;13) (q37;q14), t(11;22) (q24;q12) and t(X;18) (p11;q11), respectively, were found, and the remaining 2 had normal karyotypes. Southern blot analysis demonstrated that in 14 cases with matched normal (N) and tumor tissue (T) DNA (5 MFH, 6 RMS, 2 ES, 1 SS), RFLPs changes including loss of allele, partial gene deletion, rearrangement and amplication had occurred at 8 loci (D1S57, D2S44, MYL1-3, D2S3, D13S1, D13S30, ESD and D17S5, respectively). Among these loci, gene changes on D1S57 and D2S44 were found to be shared by MFH, RMS, ES and SS, and D17S5, D2S3 and ESD abnormalities were shared by MFH, ES and SS, as well as by MFH and RMS. These results suggest that a multilocus and multistep process may be involved in the carcinogenesis of MFH, RMS, ES and SS.