Four years later in a second examination with molecular methods for a study of adrenal sarcomas, this diagnosis must be revised due to the lack of MDM-2 gene amplification and FKHR translocation which exclude sarcoma.
Many malignancies display amplification of MDM genes encoding negative regulators of p53 and therefore much effort to date has concentrated on the development of molecules that inhibit MDM2, the most advanced of which are being tested in clinical trials for sarcoma, glioblastoma, bladder cancer and lung adenocarcinoma.
In line with this, sarcomas with MDM2-negative rings commonly show complete loss of either CDKN2A or RB1 -both known to be important for genome integrity.
We compared sensitivity and specificity of p16 IHC to MDM2 and CDK4 IHC in the differential diagnosis of ALT-WDLPS (n=19) versus benign adipocytic tumors (n=44) and DDLPS (n=18) versus mimicking sarcomas (n=20).
We used fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) to detect MDM2 amplification and protein overexpression, respectively, in 49 WDLSs, 5 DDLSs, 23 myxoid liposarcomas, 25 benign lipomatous tumors, and 75 spindle and pleomorphic sarcomas.
We propose, therefore, that MDM2 markers along with TP53 sequencing should be considered as patient biomarkers in clinical trials of sarcomas using MDM2 antagonists.
In this study, we have assessed the occurrence of p53, Rb and MDM2 alterations in the same samples of osteosarcomas, along with representative samples of various other sarcomas.
Although MDM2 is almost always positive in well-differentiated liposarcoma, which is useful in differentiating benign from atypical/well-differentiated lipomatous tumor, it should not be used in differentiating liposarcoma from other sarcomas.
The MDM2 oncogene is overexpressed in many human cancers, including sarcomas, certain hematologic malignancies, and breast, colon and prostate cancers.
A constitutional G allele has also been associated with earlier onset of various cancer types, and studies of sarcomas have shown an enrichment of the G allele in tumors with MDM2 amplification, notably atypical lipomatous tumor (also known as well-differentiated liposarcoma).
We compared the clinical data, histologic data, MDM2 status (immunohistochemistry [IHC], fluorescence in situ hybridization [FISH]), genomic profile (array comparative genomic hybridization), and follow-up of 19 patients with peripheral UPS with MDM2 amplification and 62 with peripheral conventional DDLPS retrieved from the French sarcoma network (RRePS) and the Conticabase (Connective Tissue Cancer Network database).
MDM2 is a wild-p53 inducible protein which may form a complex with p53, abrogating its function, as has been found in human sarcomas and other malignancies. p21WAF1/CIP1 is another protein inducible by wild-type p53, involved in inhibiting cell-cycle progression, through binding to cyclin/cyclin-dependent-kinase complexes.
To determine a role for ligand-mediated receptor activation in sarcoma progression, the relative expression and function of EGF-R, IGF-I-R, and several other molecular determinants implicated in the progression of mesenchymal neoplasms were evaluated in human sarcoma cells established from surgical specimens of primary and metastatic tumors. mRNA blot analyses demonstrated the expression of c-Met, p53, and MDM2-specific transcripts.
Because some sarcomas exhibit amplification and overexpression of MDM-2, which may interact with p53 and cause stabilization of wild-type p53 protein, we examined these tumors for MDM-2 amplification.