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HDAC Screening identifies the HDAC Class I Inhibitor Romidepsin as a promising Epigenetic Drug for Biliary Tract Cancer
Author(s) -
Mayr Christian,
Kiesslich Tobias,
Erber Sara,
Bekric Dino,
Dobias Heidemarie,
Beyreis Marlena,
Ritter Markus,
Jäger Tarkan,
Neumayer Bettina,
Winkelmann Paul,
Klieser Eckhard,
Neureiter Daniel
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2021.35.s1.05128
Subject(s) - romidepsin , vorinostat , histone deacetylase , cancer research , cytotoxicity , panobinostat , pharmacology , chemistry , biology , biochemistry , in vitro , histone , gene
Biliary tract cancer (BTC) is a fatal disease with limited therapeutic options. Inhibition of histone deacetylases (HDACs) represents an effective anti‐cancer approach. Data regarding HDAC and BTC are sparse but promising. There, we performed a comprehensive investigation of HDAC expression and pharmacological HDAC inhibition in a BTC in vitro model. Methods Expression of HDACs in BTC cells was measured via quantitative real‐time PCR and immunohistochemistry. Cytotoxicity of HDAC pan‐inhibitors (belinostat, vorinostat) and HDAC inhibitors targeting different HDAC classes (mocetinostat, romidepsin, LMK‐235, tubastatin A) was analyzed using the resazurin assay. HDAC1/2 activity was measured via the HDAC‐Glo I/II Assay and Screening System (Promega). Mode of cytotoxicity of romidepsin was evaluated via a time‐resolved resazurin assay and the RealTime‐Glo Annexin V Apoptosis and Necrosis Assay (Promega). Changes in H3K9Ac levels were measured to investigate the epigenetic effect of romidepsin. Combinatory treatment of romidepsin and cisplatin was evaluated via the resazurin assay and changes of IC50‐values. Expression of HDAC1/2 in n = 78 BTC patient samples was done via immunohistochemistry. Appropriate statistical tests were used to correlate HDAC1/2 expression with clinicopathological data. Results HDAC profiling revealed a heterogeneous expression of HDACs across the studied cell lines (n = 8). Furthermore, we found that BTC cells show different sensitivities towards the used HDAC inhibitors. The HDAC class I inhibitor romidepsin showed significant cytotoxicity in the (low) nM‐range and was therefore chosen for further investigation. We found that romidepsin causes apoptosis and secondary necrosis and significantly reduces HDAC activity in BTC cells. Furthermore, we observed that sub‐lethal concentrations of romidepsin augmented the toxic effect of the standard chemotherapeutic cisplatin. We also measured HDAC1 and 2 expression in BTC patients. HDAC1 expression correlated with tumor localization and tumor grading. Moreover, patients with high expression of HDAC2 had a significant shorter overall survival time. Conclusions Our results demonstrate that the HDAC class I inhibitor romidepsin is a promising anti‐BTC substance. In addition, we show that HDAC1 and 2 are expressed in BTC patient samples and associate with clinical parameters.