Enhanced levels of Hsulf-1 interfere with heparin-binding growth factor signaling in pancreatic cancer

Hsulf-I is a newly identified enzyme, which has the ability to decrease the growth of hepatocellular, ovarian, and head and neck squamous cell carcinoma cells by interfering with heparin-binding growth factor signaling. Since pancreatic cancers over-express a number of heparin-binding growth factors and their receptors, the expression and function of this enzyme in pancreatic cancer was analyzed. Results: Pancreatic cancer samples expressed significantly (22.5-fold) increased Hsulf-I mRNA levels compared to normal controls, and Hsulf-I mRNA was localized in the cancer cells themselves as well as in peritumoral fibroblasts. 4 out of 8 examined pancreatic cancer cell lines expressed Hsulf-I, whereas its expression was below the level of detection in the other cell lines. Stable transfection of the Hsulf-I negative Panc-I pancreatic cancer cell line with a full length Hsulf-I expression vector resulted in increased sulfatase activity and decreased cell-surface heparan-sulfate proteoglycan (HSPG) sulfation. Hsulf-I expression reduced both anchorage-dependent and -independent cell growth and decreased FGF-2 mediated cell growth and invasion in this cell line. Conclusion: High expression of Hsulf-I occurs in the stromal elements as well as in the tumor cells in pancreatic cancer and interferes with heparin-binding growth factor signaling.