Syntenin-1 is expressed in uveal melanoma and correlates with metastatic progression

Uveal melanoma is an aggressive cancer that metastasizes to the liver in about half of patients, being at that time almost always fatal. Identification of patients at high risk of metastases may provide indication for a frequent follow-up for early detection of metastases and treatment. The analysis of the gene expression profiling of primary human uveal melanomas showed high expression of SDCBP (encoding for syndecan-binding protein-1 or syntenin-1), which appeared higher in patients with recurrence, whereas expression of syndecans was lower and unrelated to progression. Moreover, we found that high expression of SDCBP gene was related to metastatic progression in two additional independent dataset of uveal melanoma patients. More importantly, immunohistochemistry showed that high expression of syntenin-1 protein in primary tumours was significantly related to metastatic recurrence in our cohort of patients. Syntenin-1 expression was confirmed by RT-PCR, immunofluorescence and immunohistochemistry in cultured uveal melanoma cells or primary tumours. A pseudo-metastatic model of uveal melanoma to the liver was developed in NOD/SCID/IL2R null mice and the study of syntenin-1 expression in primary and metastatic lesions revealed higher syntenin-1 expression in metastases. The inhibition of SDCBP expression by siRNA impaired the ability of uveal melanoma cells to migrate in a woundhealing assay. These results suggest that SDCBP is involved in uveal melanoma progression and that it represents a candidate molecular marker of metastases and a potential therapeutic target.

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Gangemi R, Mirisola V, Barisione G, Fabbi M, Brizzolara A, Lanza F, Mosci C, Salvi S, Gualco M, Truini M, Angelini G, Boccardo S, Cilli M, Airoldi I, Queirolo P, Jager MJ, Daga A, Pfeffer U, Ferrini S