TI - Discussion . AB - Sulfatases are a family of enzymes that catalyse the hydrolysis of sulfate ester bonds from a wide variety of compounds . They are classified into arylsulfatases and nonarysulfatases according to their ability to hydrolyse the sulfate ester bonds of aromatic compounds such as p-nitrocatechol sulfate and 4-methylumbelliferyl sulfate [14] . Hsulf-1 is a newly identified member of the sulfatase family , which exhibits arysulfatase activity and removes sulfate from the C-6 position of glucosamine within the specific sub regions of intact heparin [10] . In the present study a significant up-regulation of Hsulf-1 in primary pancreatic cancer , pancreatic metastasis and CP compared to normal pancreatic tissues was demonstrated , whereas there was no significant difference in the expression of other members of the sulfatase family in these tissues . This indicates that Hsulf-1 might play a specific role in the pathogenesis and evolution of CP and pancreatic cancer . Normal pancreatic tissues are composed mainly of a homogenous population of acinar cells ( and a low percentage of ductal and islet cells ) , whereas both CP and pancreatic cancer tissues contain a variable amount of desmoplastic areas , inflammatory cells , degenerating acini , tubular complexes ( and cancer cells ) . Thus , the observed wide range of expression of Hsulf-1 mRNA in both CP and pancreatic cancer tissues is most likely due to the different individual composition of these tissues . To confirm this hypothesis , in situ hybridization was utilized to localize Hsulf-1 mRNA expression in normal , CP and pancreatic cancer tissues . This analysis demonstrated that Hsulf-1 mRNA expression was weakly present in normal acinar cells , and at high levels in the endothelium and smooth muscle cells of blood vessels , as well as in fibroblasts and tubular complexes in CP tissues and additionally in the malignant cells in pancreatic cancer tissues . The observed increased levels of Hsulf-1 in pancreatic cancer tissues seem to be in contrast to the down-regulation of Hsulf-1 in HCC and ovarian tumors [11,12] . However , while in ovarian cancer markedly diminished levels were observed in approximately 75% of the cases [11] , the percentage was much smaller in HCCs ( 30% ) [12] , suggesting that reduced Hsulf-1 expression is not universally observed in all tumor types . It has been hypothesized that enhanced expression of Hsulf-1 is related to c-myc amplification in HCCs [12] . It could be speculated that also in pancreatic cancer high Hsulf-1 levels are related to c-myc amplification [15] , atleast in a subset of tumors . Another interesting aspect is the generally low Hsulf-1 expression level in cultured cancer cell lines . Thus , Hsulf-1 expression is absent in 71% of ovarian cancer cell lines [11] , in 82% of HCC cell lines [12] , and in 50% of pancreatic cancer cell lines ( present study ) . To evaluate the functional importance of Hsulf-1 in pancreatic cancer cells , Panc-1 cells , which do not express Hsulf-1 at detectable levels , were stably transfected with a Hsulf-1 expression vector . Over-expression of Hsulf-1 in Panc-1 cells resulted in reduced anchorage -dependent and -independent cell growth , suggesting an important growth regulatory role of this gene in pancreatic cancer . These tumors are characterized by enhanced expression of a variety of growth factors and their receptors , which have the capacity to influence different cellular functions , such as cell proliferation , migration and angiogenesis [3, 4] . Some of these growth factors are heparin-binding growth factors , such as FGFs , VEGF and HB-EGF . We hypothesized that Hsulf-1 expression would attenuate the effects of these growth factors by desulfation of HSPGs resulting in a growth disadvantage as suggested for other tumors [11-13] . FGF-2 stimulated cell proliferation was attenuated by the expression of Hsulf-1 . Nonetheless , FGF-2 still induced growth in Hsulf-1 expressing cells , but to a lesser extent compared with control cells . It is conceivable that the HSPG/FGF receptor complex can facilitate FGF-2 signaling , but may not be strictly required for binding of FGF-2 to its receptor ; it only increases the affinity of the FGF-2/FGF receptor interaction to a certain degree . Hsulf-1 expression in Panc-1 cells also partially blocked FGF-2 induced MAPK PHOSphorylation and invasion , further supporting the hypothesis that Hsulf-1 interferes with FGF-2 signaling in pancreatic cancer cells . In contrast , no difference between Hsulf-1 expressing and control cells was observed upon stimulation with HB-EGF - another heparin-binding growth factor - as well as EGF and IGF-1 suggesting that these growth factors and their receptors do not require sulfated HSPGs for effective signaling . The observation that Hsulf-1 expression does not interfere with HB-EGF signaling in pancreatic cancer cells is in contrast to recent studies in ovarian cancer cells [11] , suggesting cell type specific differences . Previously , it has been shown that Hsulf-1 expression enhances cisplatin-induced apoptosis in HCC cell lines [12] . In the present study , we did not observe increased sensitivity towards chemotherapeutic agents in Hsulf-1 expressing versus control cells . In contrast , Hsulf-1 expressing Panc-1 cells were more resistant to gemcitabine than the control cells , thereby suggesting that Hsulf-1 over-expression might confer increased chemoresistance to pancreatic cancer cells and thus provide them with a growth advantage . However , the reason behind this effect is currently not known and requires further analysis . In conclusion , Hsulf-1 is up-regulated in pancreatic cancer and chronic pancreatitis compared to normal pancreatic tissues , mainly due to over-expression in the desmoplastic and cancerous tissue elements . Expression of Hsulf-1 in Panc-1 cells negatively influences growth and invasion by attenuating FGF-2 signaling , suggesting that Hsulf-1 plays a specific role in the pathogenesis of pancreatic cancer . Further experimental approaches , especially in vivo studies , will help to assess in more detail the role of this enzyme in human pancreatic cancer .