title: Defeating EpCAM(+) liver cancer stem cells by targeting chromatin remodeling enzyme CHD4 in human hepatocellular carcinoma.
abstract: OBJECTIVE
  Hepatocellular carcinoma is composed of a subset of cells with enhanced tumorigenicity and chemoresistance that are called cancer stem (or stem-like) cells. We explored the role of chromodomain-helicase-DNA-binding protein 4, which is encoded by the CHD4 gene and is known to epigenetically control gene regulation and DNA damage responses in EpCAM(+) liver cancer stem cells.
  
  
  METHODS
  Gene and protein expression profiles were determined by microarray and immunohistochemistry in 245 and 144 hepatocellular carcinoma patients, respectively. The relationship between gene/protein expression and prognosis was examined. The functional role of CHD4 was evaluated in primary hepatocellular carcinoma cells and in cell lines in vitro and in vivo.
  
  
  RESULTS
  CHD4 was abundantly expressed in EpCAM(+) hepatocellular carcinoma with expression of hepatic stem cell markers and poor prognosis in two independent cohorts. In cell lines, CHD4 knockdown increased chemosensitivity and CHD4 overexpression induced epirubicin chemoresistance. To inhibit the functions of CHD4 that are mediated through histone deacetylase and poly (ADP-ribose) polymerase, we evaluated the effect of the histone deacetylase inhibitor suberohydroxamic acid and the poly (ADP-ribose) polymerase inhibitor AG-014699. Treatment with either suberohydroxamic acid or AG-014699 reduced the number of EpCAM(+) liver cancer stem cells in vitro, and suberohydroxamic acid and AG-014699 in combination successfully inhibited tumor growth in a mouse xenograft model.
  
  
  CONCLUSIONS
  CHD4 plays a pivotal role in chemoresistance and the maintenance of stemness in liver cancer stem cells and is therefore a good target for the eradication of hepatocellular carcinoma.
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Kouki
authors.initials: K
authors.lastname: Nio
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan. Electronic address: taroy@m-kanazawa.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Yamashita
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Hikari
authors.initials: H
authors.lastname: Okada
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Kondo
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Yoshimoto
authors.initials: Y
authors.lastname: Nomura
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Sha Sha
authors.initials: SS
authors.lastname: Zeng
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Sunagozaka
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Oishi
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Honda
authors.affiliation: Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kaneko
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000096:biosynthesis / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D042002:Chromatin Assembly and Disassembly; D000071858:Epithelial Cell Adhesion Molecule / Q000096:biosynthesis / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006498:Hepatectomy; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D056245:Mi-2 Nucleosome Remodeling and Deacetylase Complex / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D016688:Mice, Inbred NOD; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D012334:RNA, Neoplasm / Q000235:genetics*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D001324:Autoantigens; D014408:Biomarkers, Tumor; C115323:CHD4 protein, human; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D012334:RNA, Neoplasm; D056245:Mi-2 Nucleosome Remodeling and Deacetylase Complex
keywords: Chemoresistance; Chromodomain-helicase-DNA-binding protein 4; Histone deacetylase; Liver cancer stem cells; Poly (ADP-ribose) polymerase