Novel fluorinated carbonic anhydrase IX inhibitors reduce hypoxia-induced acidification and clonogenic survival of cancer cells.

// Justina Kazokaitė 1, 2 , Raymon Niemans 2 , Virginija Dudutienė 1 , Holger M. Becker 3 , Jānis Leitāns 4 , Asta Zubrienė 1 , Lina Baranauskienė 1 , Gabor Gondi 5, 6 , Reinhard Zeidler 5, 6 , Jurgita Matulienė 1 , Kaspars Tārs 1 , Ala Yaromina 2 , Philippe Lambin 2 , Ludwig J. Dubois 2, * and Daumantas Matulis 1, * 1 Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania 2 Department of Radiotherapy (The M-Lab Group), GROW – School for Oncology and Developmental Biology, Maastricht Comprehensive Cancer Centre, Maastricht University Medical Centre, Maastricht, The Netherlands 3 Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany 4 Latvian Biomedical Research and Study Center, Riga, Latvia 5 Department of Gene Vectors, Helmholtz Center for Environmental Health, Munich, Germany 6 Department of Otorhinolaryngology, Klinikum der Universitat Munchen, Munich, Germany * These authors are contributed equally to this work Correspondence to: Daumantas Matulis, email: matulis@ibt.lt , daumantas.matulis@bti.vu.lt Keywords: cancer; hypoxia; drug design; sulfonamide; carbonic anhydrase IX Received: April 12, 2018      Accepted: May 14, 2018      Published: June 01, 2018 ABSTRACT Human carbonic anhydrase (CA) IX has emerged as a promising anticancer target and a diagnostic biomarker for solid hypoxic tumors. Novel fluorinated CA IX inhibitors exhibited up to 50 pM affinity towards the recombinant human CA IX, selectivity over other CAs, and direct binding to Zn(II) in the active site of CA IX inducing novel conformational changes as determined by X-ray crystallography. Mass spectrometric gas-analysis confirmed the CA IX-based mechanism of the inhibitors in a CRISPR/Cas9-mediated CA IX knockout in HeLa cells. Hypoxia-induced extracellular acidification was significantly reduced in HeLa, H460, MDA-MB-231, and A549 cells exposed to the compounds, with the IC 50 values up to 1.29 nM. A decreased clonogenic survival was observed when hypoxic H460 3D spheroids were incubated with our lead compound. These novel compounds are therefore promising agents for CA IX-specific therapy.