A Histone Deacetylase Inhibitor Suppresses Epithelial-Mesenchymal Transition and Attenuates Chemoresistance in Biliary Tract Cancer

• Published in: PloS one 2016-01, Vol.11 (1), p.e0145985-e0145985
• Main Authors: Sakamoto, Takuya, Kobayashi, Shogo, Yamada, Daisaku, Nagano, Hiroaki, Tomokuni, Akira, Tomimaru, Yoshito, Noda, Takehiro, Gotoh, Kunihito, Asaoka, Tadafumi, Wada, Hiroshi, Kawamoto, Koichi, Marubashi, Shigeru, Eguchi, Hidetoshi, Doki, Yuichiro, Mori, Masaki
• Format: Article
• Language: English
• Subjects: Animals; Antineoplastic Agents - therapeutic use; Apoptosis; Attenuation; Biliary tract; Biliary tract cancer; Biliary Tract Neoplasms - drug therapy; Biliary Tract Neoplasms - pathology; Biotechnology; Bone morphogenetic proteins; Breast cancer; Cancer; Care and treatment; Cell Line, Tumor; Cell survival; Chemoresistance; Chemotherapy; Cholangiocarcinoma; Chromatin; Cytokines; Diagnosis; Drug Resistance, Neoplasm; E-cadherin; Epigenetics; Epithelial-Mesenchymal Transition - drug effects; Gemcitabine; Gene expression; Growth factors; Health aspects; Histone deacetylase; Histone Deacetylase Inhibitors - pharmacology; Humans; Inhibition; Inhibitors; Intermediate filament proteins; Kinases; Lung cancer; Malignancy; Medical prognosis; Medicine; Mesenchyme; Metastases; Metastasis; Mice; Nuclear transport; Regulators; Risk factors; Signal transduction; Signaling; Smad4 protein; Snail protein; Studies; Surgery; Transcription factors; Transforming Growth Factor beta1 - physiology; Transforming growth factor-b1; Translocation; Tumors; Vimentin; Xenograft Model Antitumor Assays; Xenografts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0145985

Epithelial-mesenchymal transition (EMT) is involved in the characteristics of malignancy, such as invasion, metastasis, and chemoresistance. In biliary tract cancer (BTC), EMT is induced by transforming growth factor-beta 1 (TGF-β1). The EMT is reversible; therefore, it is conceivable that it could be related to some epigenetic changes. We focused on histone deacetylase (HDAC) inhibitors as regulators of TGF-β1 signaling, and investigated their effect on EMT and chemoresistance. We employed four BTC cell lines (MzChA-1, gemcitabine-resistant MzChA-1, TFK-1, and gemcitabine-resistant TFK-1) and used vorinostat as the HDAC inhibitor. The relative mRNA expression of an epithelial marker (CDH1) and mesenchymal markers (CDH2, vimentin, SNAI1) were measured by qRT-PCR to evaluate factors associated with EMT. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to evaluate the chemoresistance of each cell line. In addition, NOD/SCID mice were used to evaluate the effect of vorinostat in vivo. In the parent MzChA-1 and TFK-1 cell lines, TGF-β1 induced EMT and chemoresistance; while vorinostat inhibited the EMT and chemoresistance induced by TGF-β1. In gemcitabine-resistant cell lines that highly expressed TGF-β1, vorinostat inhibited EMT and attenuated chemoresistance. We showed that vorinostat inhibits nuclear translocation of SMAD4 which is a signaling factor of TGF-β1, and this is one of the mechanisms by which vorinostat regulates EMT. We also showed that vorinostat attenuates the binding affinity of SMAD4 to the CDH1-related transcription factors SNAI1, SNAI2, ZEB1, ZEB2, and TWIST. Furthermore, combination therapy with vorinostat and gemcitabine improved survival time in the mice xenografted with gemcitabine resistant MzChA-1 cells. In conclusion, vorinostat regulated TGF-β1-induced EMT and chemoresistance through inhibition of SMAD4 nuclear translocation.