Twist expression promotes migration and invasion in hepatocellular carcinoma

• Main Authors: Kobayashi Yoshiyuki, Nakamura Shinichiro, Takaki Akinobu, Uemura Masayuki, Nakanishi Yutaka, Nishina Shinichi, Tanaka Shigetomi, Ueda Naoki, Takaoka Nobuyuki, Fujikawa Tatsuya, Shiraha Hidenori, Matsuo Noriyuki, Nouso Kazuhiro, Yagi Takahito, Yamamoto Kazuhide
• Format: Article
• Language: English
• Published: BMC 2009-07-01
• Series: BMC Cancer
• Online Access: http://www.biomedcentral.com/1471-2407/9/240

<p>Abstract</p> <p>Background</p> <p>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).</p> <p>Methods</p> <p>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 <it>in vitro </it>wound healing assay. We used immunofluorescent vinculin staining to visualize focal adhesion.</p> <p>Results</p> <p>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.</p> <p>Conclusion</p> <p>Twist induces migratory effect on hepatocellular carcinoma by causing epithelial-mesenchymal transition.</p>