HSulf-1Inhibits The Migration And Proliferation Of SMMC-7721Cells By Downregulating The Growth Factor Signaling

Background&0bjectiveThe human sulfatase1gene (hSulf-1) encodes an extracellular6-O-endosulfatase andregulates the sulfation status of heparan sulfate proteoglycans (HSPG). It has been reportedthat hSulf-1has been down-expressed in many tumors, such as hepatocellular carcinoma(HCC). Recent studies indicated that hSulf-1suppresses tumorigenesis and angiogenesis byinhibiting the activation of several singaling pathways,including fbroblast growth factor(FGF)-2, epidermal growth factor (EGF) signaling and so on. Meanwhile, the AKT andERK signaling pathways are the most critical pathways in normal cell survival, proliferation,metabolism, migration, and angiogenesis. The possible correlation between hSulf-1andPI3K (Phosphatidylinositol-3-OH kinase)/AKT, ERK signaling in SMMC-7721cell lineneeds further exploration. The study aimed to explore the influences of hSulf-1on themigration and proliferation of SMMC-7721hepatocellular carcinoma cells and itsmechanism. Meanwhile, we also detected the expression of hSulf-1in clinical HCCspecimens and pericarcinomatous tissues and determine its clinical significance.MethodsWe restored hSulf-1expression in the hepatoma cancer cell line SMMC-7721withhSulf-1adenovirus; The effect of hSulf-1on the expression and phosphorylation of AKTand ERK in SMMC-7721cells were analyzed by Western blot. The impact of hSulf-1on themigration and proliferation of SMMC-7721cells was measured by scarification test andMTT. The expression of hSulf-1protein were examined by immunohistochemistry in HCCand pericarcinomatous tissues．SPSS17.0statistical software was used to analyze therelationship between the expression of hSulf-1and clinical parameters.ResultsWestern blot assay showed thatthe Ad-hSulf-1group has a higher hSulf-1proteinexpression, lower p-AKT, p-ERK and other protein expression and a higher PTEN proteinexpression compared with Ad-EGFP group and blank control group, and it is more obviousat MOI=100than at MOI=50. The migration distance and viability of SMMC-7721cellstreated with hSulf-1for48h were obviously decreased. Compared with637±30.5μm,470±60.8μm in the negative control group and Ad-EGFP group, respectively, the Ad-hSulf-1group moved317±51.3μm(MOI=50),233±32.1μm(MOI=100). In clinicalspecimens,17of70HCC tissues (24.3％) and31of70pericarcinomatous tissues(44.3％)were overexpressed. The expression level of hSulf-1was correlated with hepatic cirrhosisand pathologic grades. Survival analysis showed that the median survival time of the HCCpatients with high expression of hSulf-1was longer than those with negative expression ofhSulf-1.ConclusionCompared with cells treated with Ad5-EGFP and cells in the blank control group,Western blot analysis showed that hSulf-1could decrease the phosphorylation of AKT andERK in SMMC-7721cells. hSulf-1may inhibit SMMC-7721cell migration andproliferation through reducing the phosphorylation of AKT, ERK signaling pathway. Theexpression of hSulf-1was low in the HCC tissues. This result showed a possibility that thehSulf-1expression may play an important role in the development and progression of HCC.Therefore, the above analysis suggested that hSulf-1may become a new potential target inHCC treatment.