| Research Abstract |
We have carried out extensive investigations into the molecular biologic characteristics of several kinds of soft-tissue sarcomas and the following results have been obtained.
1. Dedifferentiated liposarcoma or chondrosarcoma: The frequency of p53 gene alterations and H-ras gene alteration in dedifferentiated component was higher than those in well differentiated component within the same tumor.
2. Synovial sarcoma: The detection of SYT-SSX fusion transcripts is a useful diagnostic tool in this tumor, however, its subtype has no correlation with patient's prognosis. An increased rate of apoptosis, a low p27/kip1-labeling index, reduced expression of E-cadherin and alpha-catenin, aberrant expression of beta-catenin, beta-catenin gene mutation, and co-expression of hepatocyte growth factor (HGF) and c-MET are all adverse prognostic factors. E-cadherin gene alteration has no correlation with prognosis, however, it is one of the causes of epithelial-mesenchymal transition in this tumor. Molecular abnormalities of p53, MDM2 and ras gene have no correlation with prognosis.
3. Malignant rhabdoid tumor (MRT):
p53 gene alterations occur frequently. All examined cases showed hSNF5/INI1 gene alterations.
4. Malignant peripheral nerve sheath tumor (MPNST): The expression of p53 protein, TGF- beta 1, TGF-beta receptor type II, HGF and c-MET is higher in the areas of MPNST than in the neurofibromatous areas within the same tumor in patients with von Recklinghausen's disease. High MIB-1 labeling index and the presence of rhabdomyoblasts (Malignant Triton tumor) were adverse prognostic factors in MPNST. The alteration of p53 did not affect the patients survival.
5. Sporadic desmoid tumor: Beta-catenin accumulation has a significant relationship with cyclin D1 overexpression. In a beta-catenin mutated group, cyclin D1 mRNA expression was found to be significantly higher than that in a beta-catenin wild-type group.
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