title: Proliferation and migration mediated by Dkk-1/Wnt/beta-catenin cascade in a model of hepatocellular carcinoma cells.
abstract: Beta-catenin is a multifunctional protein acting as a key factor in the cadherin-mediated cell-cell adhesion system and in the Wnt signaling pathway. To demonstrate the molecular mechanisms of metastasis of hepatocellular carcinoma (HCC) cells, we established a metastatic subclone of human HCC H7402 cells, termed M-H7402, by isolating from transplantation of H7402 cells into severe combined immunodeficient (SCID) mice. Based on the 2 parallel cell lines, we investigated the roles of dickkopf-1 (Dkk-1) and Wnt/beta-catenin pathway in proliferation and migration of HCC cells. cDNA microarray showed that 24 genes were related to tumor metastasis differentially expressed between H7402 and M-H7402 cells. Western blot analysis revealed that the expression levels of beta-catenin, c-Myc, and cyclin D1 were upregulated, but Dkk-1 and nm23 were dramatically downregulated in M-H7402 cells, which suggests that the 2 cell lines were remarkably different in molecular events associated with metastasis. Furthermore, we found that overexpression of Dkk-1 by transfection was able to downregulate the expression of c-Myc and cyclin D1, and it also inhibited the growth and migration in M-H7402 cells. Although reduction of Dkk-1 expression by RNA interference was able to upregulate the expression of beta-catenin, c-Myc, and cyclin D1 in H7402 cells, it also promoted beta-catenin translocation from cytoplasm into nuclei and increased the migration of the cells. Therefore, we conclude that Dkk-1/Wnt/beta-catenin cascade may mediate the proliferation and migration of HCC cells during the metastasis process.
authors.affiliation: Department of Biochemistry, Institute For Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Xiaoran
authors.initials: X
authors.lastname: Qin
authors.forename: Hang
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zhou
authors.forename: Changye
authors.initials: C
authors.lastname: Wang
authors.forename: Huizhong
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.forename: Lihong
authors.initials: L
authors.lastname: Ye
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D020869:Gene Expression Profiling; D006801:Humans; D007165:Immunosuppression Therapy; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D020411:Oligonucleotide Array Sequence Analysis; D034741:RNA, Small Interfering / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D023041:Xenograft Model Antitumor Assays; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: C501127:Dkk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; D051153:Wnt Proteins; D051176:beta Catenin