www.oncotarget.com Oncotarget, 2020, Vol. 11, (No. 20), pp: 1799-1815 Research Paper Entinostat augments NK cell functions via epigenetic upregulation of IFIT1-STING-STAT4 pathway John M. Idso1, Shunhua Lao1, Nathan J. Schloemer1,2, Jeffrey Knipstein2, Robert Burns3, Monica S. Thakar1,2,* and Subramaniam Malarkannan1,2,4,5,* 1Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Versiti, Milwaukee, WI, USA 2Division of Pediatric Hematology-Oncology-BMT, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA 3Bioinformatics Core, Blood Research Institute, Versiti, Milwaukee, WI, USA 4Divson of Hematology-Oncology, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA 5Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA *Co-senior authors Correspondence to: Monica S. Thakar, email:
[email protected] Subramaniam Malarkannan, email:
[email protected] Keywords: NK cells; histone deacetylase inhibitor; Ewing sarcoma; rhabdomyosarcoma; immunotherapy Received: September 10, 2019 Accepted: March 03, 2020 Published: May 19, 2020 Copyright: Idso et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT Histone deacetylase inhibitors (HDACi) are an emerging cancer therapy; however, their effect on natural killer (NK) cell-mediated anti-tumor responses remain unknown. Here, we evaluated the impact of a benzamide HDACi, entinostat, on human primary NK cells as well as tumor cell lines. Entinostat significantly upregulated the expression of NKG2D, an essential NK cell activating receptor. Independently, entinostat augmented the expression of ULBP1, HLA, and MICA/B on both rhabdomyosarcoma and Ewing sarcoma cell lines.