Impact of Sulfatase-2 on cancer progression and prognosis in patients with renal cell carcinoma.

Heparan sulfate-specific endosulfatase-2 (SULF-2) can modulate the signaling of heparan sulfate proteoglycan-binding proteins. The involvement of SULF-2 in cancer growth varies by cancer type. The roles of SULF-2 expression in the progression and prognosis of renal cell carcinomas (RCC) have not yet been fully clarified. In the present study, the expression levels of SULF-2 mRNA and protein in 49 clinical RCC samples were determined by RT-PCR and immunostaining. The existence of RCC with higher SULF-2 expression and lower SULF-2 expression compared to the adjacent normal kidney tissues was suggested. High SULF-2 expression was correlated with an early clinical stage and less invasive pathological factors. Low SULF-2 expression was correlated with an advanced stage and higher invasive factors. Three-year cancer-specific survival (CSS) for high SULF-2 RCC and low SULF-2 RCC were 100% and 71.4%, respectively (log-rank P = 0.0019), with a significantly shorter CSS observed in low SULF-2 RCC patients. The influence of SULF-2 expression level on Wnt/VEGF/FGF signaling, cell viability and invasive properties was examined in three RCC cell lines, Caki-2, ACHN and 786-O, using a SULF-2 suppression model involving siRNA or a SULF-2 overexpression model involving a plasmid vector. High SULF-2 expression enhanced Wnt signaling and Wnt-induced cell viability, but not cell invasion. In contrast, low levels of SULF-2 expression significantly enhanced both cell invasion and viability through the activation of VEGF/FGF pathways. RCC with lower SULF-2 expression might have a higher potential for cell invasion and proliferation, leading to a poorer prognosis via the activation of VEGF and/or FGF signaling.