title: Twist expression promotes migration and invasion in hepatocellular carcinoma.
abstract: BACKGROUND
  Twist, a transcription factor of the basic helix-loop-helix class, is reported to regulate cancer metastasis. It is known to induce epithelial-mesenchymal transition (EMT). In this study, we evaluated the expression of twist and its effect on cell migration in hepatocellular carcinoma (HCC).
  
  
  METHODS
  We examined twist expression using immunohistochemistry in 20 tissue samples of hepatocellular carcinoma, and assessed twist expression in HCC cell lines by RT-PCR and Western blot analysis. Ectopic twist expression was created by introducing a twist construct in the twist-negative HCC cell lines. Endogenous twist expression was blocked by twist siRNA in the twist-positive HCC cell lines. We studied EMT related markers, E-cadherin, Vimentin, and N-cadherin by Western blot analysis. Cell proliferation was measured by MTT assay, and cell migration was measured by in vitro wound healing assay. We used immunofluorescent vinculin staining to visualize focal adhesion.
  
  
  RESULTS
  We detected strong and intermediate twist expression in 7 of 20 tumor samples, and no significant twist expression was found in the tumor-free resection margins. In addition, we detected twist expression in HLE, HLF, and SK-Hep1 cells, but not in PLC/RPF/5, HepG2, and Huh7 cells. Ectopic twist-expressing cells demonstrated enhanced cell motility, but twist expression did not affect cell proliferation. Twist expression induced epithelial-mesenchymal transition together with related morphologic changes. Focal adhesion contact was reduced significantly in ectopic twist-expressing cells. Twist-siRNA-treated HLE, HLF, and SK-Hep1 cells demonstrated a reduction in cell migration by 50, 40 and 18%, respectively.
  
  
  CONCLUSIONS
  Twist induces migratory effect on hepatocellular carcinoma by causing epithelial-mesenchymal transition.
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. ayakouharujp@yahoo.co.jp
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Matsuo
authors.forename: Hidenori
authors.initials: H
authors.lastname: Shiraha
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujikawa
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takaoka
authors.forename: Naoki
authors.initials: N
authors.lastname: Ueda
authors.forename: Shigetomi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nishina
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Uemura
authors.forename: Akinobu
authors.initials: A
authors.lastname: Takaki
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nouso
authors.forename: Takahito
authors.initials: T
authors.lastname: Yagi
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002448:Cell Adhesion / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D005260:Female; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D051879:Twist-Related Protein 1 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D009687:Nuclear Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C103173:TWIST1 protein, human; D051879:Twist-Related Protein 1