title: DKK1 promotes hepatocellular carcinoma cell migration and invasion through β-catenin/MMP7 signaling pathway.
abstract: BACKGROUND
  Recently several reports have indicated that elevated expression of DKK1 is tightly associated with the progression of hepatocellular carcinoma (HCC). However, the biological function of DKK1 in HCC has not yet been well documented.
  
  
  METHODS
  In this study, the role of DKK1 in tumor cell proliferation, migration and invasion was investigated using MTT, colony formation, wound scratch, transwell assays, and also human HCC samples.
  
  
  RESULTS
  Both gain- and loss-of-function studies showed that DKK1 did not influence the tumor cell proliferation and colony formation, while dramatically promoted HCC cell migration and invasion. Subsequent investigations revealed that β-catenin was an important target of DKK1. The blocking of β-catenin by pharmacological inhibitor antagonized the function of DKK1, whereas introduction of β-catenin by transfection with plasmids or treatment with GSK3β inhibitor phenocopied the pro-migration and pro-invasion effects of DKK1. We further disclosed that DKK1 exerted its pro-invasion function, at least in part, by promoting β-catenin expression, in turn, upregulating the expression of matrix metalloproteinase 7 (MMP7), which was independent of the canonical Wnt signaling pathway. Moreover, introduction of MMP7 significantly enhanced the ability of HCC cells to invade extracellular matrix gel in vitro. Consistently, in human HCC tissues, DKK1 level was positively correlated with β-catenin expression, as well as tumor metastasis.
  
  
  CONCLUSIONS
  Taken together, these results demonstrated that DKK1 is overexpressed in HCC; moreover, ectopic expression DKK1 promotes HCC cell migration and invasion at least partly through β-catenin/MMP7 signaling axis, suggesting that DKK1 may be a promising target for HCC therapy.
authors: Liang
authors: L
authors: Chen
authors: Ming
authors: M
authors: Li
authors: Qian
authors: Q
authors: Li
authors: Institute of Chemical Biology, Pharmaceutical College of Henan University, Kaifeng 475004, China. wcjsxq@henu.edu.cn.
authors: Chao-Jie
authors: CJ
authors: Wang
authors: Song-Qiang
authors: SQ
authors: Xie
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002460:Cell Line; D002465:Cell Movement; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D020783:Matrix Metalloproteinase 7 / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D015398:Signal Transduction; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: C501126:DKK1 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D051176:beta Catenin; D020783:Matrix Metalloproteinase 7