The correlation between ring chromosomes and MDM2 gene amplification indicates that the marker rings of MFH and of atypical lipoma often harbor genetic material derived from chromosome 12.
Abnormalities of the p53 gene were found in several classes of soft tissue sarcoma, including leiomyosarcomas, rhabdomyosarcomas and malignant fibrous histiocytomas.
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.
On protein level, expression of p16(INK4a) was observed in undifferentiated pleomorphic sarcoma (UPS) in 69.1%, leiomyosarcoma in 85.7%, synovial sarcoma in 77.8%, liposarcoma in 88.9%, angiosarcoma in 60.9% and MPNST in 22.2%.
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.
Cases with accumulation had a higher MIB-1 labeling index than those without, among both the sclerosing-type well-differentiated liposarcomas (P <.05) and the malignant fibrous histiocytomas.
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.
The MFH component showed diffuse 3+ staining for epidermal growth factor receptor protein, predominantly located on the cell membrane and to a lesser extent within the cytoplasm.
FPS-1 cells might be useful for investigating biological behavior and developing new molecular targeting antitumor drugs for UPS with EGFR or COX-2 expression.
Moreover, although expression of phosphorylated epidermal growth factor receptor was detected in those two cases of malignant fibrous histiocytoma, constitutive activation of extracellular signal-related protein kinase 1/2 was not observed, suggesting that activation of epidermal growth factor receptor does not necessarily and constantly lead to signal transduction to the downstream molecules.
Cases with accumulation had a higher MIB-1 labeling index than those without, among both the sclerosing-type well-differentiated liposarcomas (P <.05) and the malignant fibrous histiocytomas.
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.