Whereas MDM2 amplification and/or over-expression were found only in two (U2OS and OSA cell lines) of 18 osteosarcomas, one of 20 malignant fibrous histiocytomas (MFHs), and in none of 14 leiomyosarcomas, such alterations were observed in two of two fibrosarcomas, three of six malignant schwannomas, three of 19 liposarcomas, and in the one hemangiopericytoma examined.
Notably, the splicing events of certain STS key genes were significantly associated with STS 2-year overall survival in the present study, including exon skip (ES) events in MDM2 and EWSR1, alternate terminator events in CDKN2A and HMGA2 for dedifferentiated liposarcoma, ES in MDM2 and alternate promoter events in CDKN2A for leiomyosarcoma, and ES in EWSR1 for undifferentiated pleomorphic sarcoma.
Abnormalities of the p53 gene were found in several classes of soft tissue sarcoma, including leiomyosarcomas, rhabdomyosarcomas and malignant fibrous histiocytomas.
In contrast, p53 gene mutations were detected at a lower frequency in malignant fibrous histiocytomas (2/34 cases) and not at all in nine chondrosarcomas and five leiomyosarcomas.
Fifty-two cases of malignant fibrous histiocytoma (MFH) were evaluated for amplification of the MDM2 gene, mutation of the P53 gene, accumulation of the P53 gene product, and their relation to disease-free and overall survival.
Although p14 inactivation or overexpression of the human murine double minute homolog (HDM2) were frequent in LMS and UPS and could substitute for TP53 mutation or deletion, such alterations were rare in angiosarcomas.
Although AFX shows a lower degree in the MIB-1 LI than MFH, the MIB-1 LI shows a limited value in relation to the biologic activity of fibrohistiocytic tumors.
Although AFX shows a lower degree in the MIB-1 LI than MFH, the MIB-1 LI shows a limited value in relation to the biologic activity of fibrohistiocytic tumors.
Among malignant mesenchymal tumors, H-ras-1 mutations have been found in malignant fibrous histiocytoma, leiomyosarcoma and embryonal rhabdomyosarcoma.
However, the TLS/FUS-CHOP fusion transcripts were not detected in two pleomorphic liposarcomas or in three myxoid variants of malignant fibrous histiocytomas.
A comparative polymerase chain reaction (PCR)-based sequence analysis of the mdr1 promoter revealed point mutations in seven out of nine osteosarcomas at nucleotides +103 (2 cases T-->C) and +137 (5 cases G-->T).No changes were seen in eight MFHs.
A comparative polymerase chain reaction (PCR)-based sequence analysis of the mdr1 promoter revealed point mutations in seven out of nine osteosarcomas at nucleotides +103 (2 cases T-->C) and +137 (5 cases G-->T).No changes were seen in eight MFHs.
We have screened mutations of the beta-catenin gene by using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method in 62 malignant bone and soft-tissue tumors, including malignant fibrous histiocytomas (MFHs), osteosarcomas, synovial sarcomas, liposarcomas, malignant schwannomas, and other types of tumors, as well as 11 benign tumors. beta-Catenin-activating missense mutations were found in two malignant tumors.
In this study, the clonality of MFH was determined by analyzing the patterns of X chromosome inactivation at the human androgen receptor gene (HUMARA) using DNA samples from archival snap-frozen and paraffin-embedded tissues.
Identification of IDH1 or IDH2 mutations supports the diagnosis of dedifferentiated chondrosarcoma rather than UPS of bone while also providing some insight into the pathogenesis of these 2 lesions.
Sixteen tumors were informative: four (leiomyosarcoma, liposarcoma, malignant Schwannoma, and a benign mesenchymal tumor, probably leiomyoma) had identical karyotypes in different samples, whereas the remaining 12 tumors (seven malignant fibrous histiocytomas [MFH], two leiomyosarcomas, two liposarcomas, and one synovial sarcoma) displayed intersample heterogeneity.