Functional genomics analysis reveals a MYC signature associated with a poor clinical prognosis in liposarcomas.

Liposarcomas, which are malignant fatty tumors, are the second most common soft-tissue sarcomas. Several histologically defined liposarcoma subtypes exist, yet little is known about the molecular pathology that drives the diversity in these tumors. We used functional genomics to classify a panel of diverse liposarcoma cell lines based on hierarchical clustering of their gene expression profiles, indicating that liposarcoma gene expression profiles and histologic classification are not directly correlated. Boolean probability approaches based on cancer-associated properties identified differential expression in multiple genes, including MYC, as potentially affecting liposarcoma signaling networks and cancer outcome. We confirmed our method with a large panel of lipomatous tumors, revealing that MYC protein expression is correlated with patient survival. These data encourage increased reliance on genomic features in conjunction with histologic features for liposarcoma clinical characterization and lay the groundwork for using Boolean-based probabilities to identify prognostic biomarkers for clinical outcome in tumor patients.

Epithelial cell adhesion molecule is expressed in a subset of sarcomas and correlates to the degree of cytological atypia in leiomyosarcomas.

Epithelial cell adhesion molecule (EpCAM) is a protein involved in cell-to-cell attachment and is considered to be strictly expressed in epithelial tissues and epithelial-derived tumors. Furthermore, EpCAM has been shown to be a negative prognostic marker for several carcinomas. In this study, we performed a genomic meta-analysis of gene expression profiles housed in the Cancer Cell Line Encyclopedia to demonstrate that EpCAM mRNA is expressed at low to moderate levels in certain sarcoma cell lines. We utilized immunohistochemical staining to confirm that the EpCAM protein is expressed in a subset of angiosarcomas and leiomyosarcomas and in all the investigated osteosarcomas. Finally, we conducted a statistical analysis of clinical data to demonstrate that EpCAM protein expression is significantly and directly correlated with the degree of cytological atypia in leiomyosarcomas. In conclusion, this data suggests that, contrary to conventional beliefs, EpCAM is expressed in a subset of sarcomas and is a negative prognostic marker for leiomyosarcomas.