title: Identifying drug-target selectivity of small-molecule CRM1/XPO1 inhibitors by CRISPR/Cas9 genome editing.
abstract: Validation of drug-target interaction is essential in drug discovery and development. The ultimate proof for drug-target validation requires the introduction of mutations that confer resistance in cells, an approach that is not straightforward in mammalian cells. Using CRISPR/Cas9 genome editing, we show that a homozygous genomic C528S mutation in the XPO1 gene confers cells with resistance to selinexor (KPT-330). Selinexor is an orally bioavailable inhibitor of exportin-1 (CRM1/XPO1) with potent anticancer activity and is currently under evaluation in human clinical trials. Mutant cells were resistant to the induction of cytotoxicity, apoptosis, cell cycle arrest, and inhibition of XPO1 function, including direct binding of the drug to XPO1. These results validate XPO1 as the prime target of selinexor in cells and identify the selectivity of this drug toward the cysteine 528 residue of XPO1. Our findings demonstrate that CRISPR/Cas9 genome editing enables drug-target validation and drug-target selectivity studies in cancer cells.
authors.affiliation: Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven-University of Leuven, 3000 Leuven, Belgium.
authors.forename: Jasper E
authors.initials: JE
authors.lastname: Neggers
authors.affiliation: Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven-University of Leuven, 3000 Leuven, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Vercruysse
authors.affiliation: Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven-University of Leuven, 3000 Leuven, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Jacquemyn
authors.affiliation: Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven-University of Leuven, 3000 Leuven, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Vanstreels
authors.affiliation: Karyopharm Therapeutics, Newton, MA 02459, USA.
authors.forename: Erkan
authors.initials: E
authors.lastname: Baloglu
authors.affiliation: Karyopharm Therapeutics, Newton, MA 02459, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Shacham
authors.affiliation: Karyopharm Therapeutics, Newton, MA 02459, USA.
authors.forename: Marsha
authors.initials: M
authors.lastname: Crochiere
authors.affiliation: Karyopharm Therapeutics, Newton, MA 02459, USA.
authors.forename: Yosef
authors.initials: Y
authors.lastname: Landesman
authors.affiliation: Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven-University of Leuven, 3000 Leuven, Belgium. Electronic address: dirk.daelemans@rega.kuleuven.be.
authors.forename: Dirk
authors.initials: D
authors.lastname: Daelemans
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D064112:Clustered Regularly Interspaced Short Palindromic Repeats / Q000235:genetics*; D016503:Drug Delivery Systems; D059765:Homologous Recombination; D006801:Humans; D006834:Hydrazines / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D019169:Jurkat Cells; D028884:Karyopherins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009154:Mutation; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D014230:Triazoles / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D000097606:Exportin 1 Protein
chemical_list: D000970:Antineoplastic Agents; D006834:Hydrazines; D028884:Karyopherins; D018160:Receptors, Cytoplasmic and Nuclear; D014230:Triazoles; D000097606:Exportin 1 Protein; C585161:selinexor