ABSTRACT: Nodular fasciitis (NF) is a rapidly growing cellular mass composed of fibroblasts/myofibroblasts, usually localized in subcutaneous tissues, that typically undergoes fibrosis and almost never recurs. Desmoid tumors (DT) are rare forms of fibroblastic/myofibroblastic growth that arise in deep soft tissues, display propensity for local infiltration and recurrence but fail to metastasize. Given that both entities are primarily fibroblastic/myofibroblastic lesions with overlapping histological features, we compared their gene expression profile to identify differentially expressed genes that may provide not only potential diagnostic markers but also clues as to the pathogenesis of each disorder. Differentially expressed transcripts (89 clones displaying increased expression in DT and 246 clones displaying increased expression in NF), included genes encoding several receptor and non-receptor tyrosine kinases (EPHB3, PTPRF, GNAZ, SYK, LYN, EPHA4, BIRC3), transcription factors (TWIST1, PITX2, EYA2, OAS1, MITF, TCF20), and members of the Wnt signaling pathway (AXIN2, WISP1, SFRP). Remarkably, almost one fourth of the differentially expressed genes encode proteins associated with inflammation and tissue remodeling, including members of the interferon (IFN), tumor necrosis factor (TNF) and transforming growth factor beta (TGF-beta) signaling pathways as well as metalloproteinases (MMP1, 9, 13, 23), urokinase plasminogen activator (PLAU) and cathepsins. Our observations provide the first comparative molecular characterization of desmoid tumors and nodular fasciitis and suggest that selected tyrosine kinases, transcription factors and members of the Wnt, TGF-beta, IFN and TNF signaling pathways may be implicated in influencing and distinguishing their fate. Keywords: comparative genomic hybridization
