Trichostatin A and sirtinol suppressed survivin expression through AMPK and p38MAPK in HT29 colon cancer cells Ya-Fen Hsu a, b , Joen-Rong Sheu c, d , Chien-Huang Lin c , De-Shin Yang c , George Hsiao c, d , George Ou d , Pei-Ting Chiu d , Yu-Han Huang c , Wen-Hsin Kuo c , Ming-Jen Hsu c, d, ⁎ a Division of General Surgery, Department of Surgery, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan b Division of General Surgery, Department of Surgery, Landseed Hospital, Taoyuan, Taiwan c Graduate Institute of Medical Sciences, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan d Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan abstract article info Article history: Received 6 July 2011 Received in revised form 4 November 2011 Accepted 21 November 2011 Available online 1 December 2011 Keywords: Trichostatin A Sirtinol Histone deacetylase Survivin Colon cancer Background: Elevated levels of survivin and histone deacetylases (HDACs) are often found over-expressed in human cancers, including colorectal cancer, and have been implicated in tumorigenesis. HDAC inhibition in- duces growth arrest and cell death in various transformed cell; however, the mechanisms by which this re- duces cell viability in colorectal cancer cells remain unexplained. Methods: We explored the actions of two HDAC inhibitors, trichostatin A (TSA) and sirtinol, in HT29 colon cancer cells. Results: TSA and sirtinol induced apoptosis and inhibited cell proliferation in HT29 cells. These results are as- sociated with the modulation of survivin. Survivin promoter luciferase activity and Sp1, a transcription factor that contributes to survivin expression, were suppressed in cells exposed to TSA or sirtinol. TSA and sirtinol also activated p38 mitogen-activated protein kinase (p38MAPK) and AMP-activated protein kinase (AMPK). Inhibitors of p38MAPK or AMPK signaling abrogated TSA and sirtinol's effects of decreasing cell viability. Sur- vivin promoter luciferase activity in the presence of TSA or sirtinol was restored by AMPK dominant negative mutant or p38MAPK inhibitor. Furthermore, Sp1 binding to the survivin promoter region decreased while p63 binding to the promoter region increased after TSA or sirtinol exposure. Conclusions: We report a p38MAPK- and AMPK-mediated downregulation of survivin, and its functional cor- relation with decreased colon cancer cell viability in the presence of HDAC inhibitor. p63 and Sp1 may also contribute to TSA and sirtinol actions. General significance: This study delineates, in part, the underlying mechanisms of TSA and sirtinol in decreas- ing survivin expression and subsequent colon cancer cell viability. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Interactions between DNA and histones regulate the activation or repression of gene transcription. Several chemical modifications, par- ticularly the acetylation of lysine residues, may change the status of histones and impact gene transcription. Excessive de-acetylation of histones has been linked to cancer pathologies as they promote the repression of tumor regulatory genes. Histone acetylation is regulated by two opposing enzymes: histone acetylases and histone de- acetylases (HDACs). HDACs can be divided into four classes: class I consists of HDAC 1, 2, 3 and 8, class II consists of HDAC 4, 5, 6, 7, 9 and 10, class III consists of sirtuins (SIRT1–7), and class IV consists of HDAC 11, which exhibits features of both classes I and II HDACs. HDAC inhibitors may cause an increase in the acetylation of histones, leading to the re-expression of silenced tumor regulatory genes [1,2]. Importantly, HDACs de-acetylate not only histones but also non- histone substrates, which contribute to a variety of cellular responses [1]. HDAC inhibitors have the ability to induce cell cycle arrest, cell differentiation, and apoptosis, as well as the ability to attenuate me- tastasis in numerous cancer cell types including colorectal cancer cells [3,4]. However, the molecular mechanisms underlying HDAC inhibitor's actions in arresting cell cycle and decreasing cell viability have not been delineated. Surgery, chemo-therapy, and radio- therapy have failed to significantly improve the prognosis of patients with advanced colorectal cancer. In addition, few patients benefit from modern target therapy. Therefore, we used trichostatin A Biochimica et Biophysica Acta 1820 (2012) 104–115 Abbreviations: HDAC, histone deacetylase; TSA, trichostatin A; AMPK, AMP- activated protein kinase; SIRT, sirtuin; IAP, inhibitor-of-apoptosis; ChIP, chromatin immunoprecipitation. ⁎ Corresponding author at: Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-hsing St., Taipei 11031, Taiwan. Tel./fax: +886 2 27361661x3198. E-mail address: aspirin@tmu.edu.tw (M.-J. Hsu). 0304-4165/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.bbagen.2011.11.011 Contents lists available at SciVerse ScienceDirect Biochimica et Biophysica Acta journal homepage: www.elsevier.com/locate/bbagen