title: NUDT15 Hydrolyzes 6-Thio-DeoxyGTP to Mediate the Anticancer Efficacy of 6-Thioguanine.
abstract: Thiopurines are a standard treatment for childhood leukemia, but like all chemotherapeutics, their use is limited by inherent or acquired resistance in patients. Recently, the nucleoside diphosphate hydrolase NUDT15 has received attention on the basis of its ability to hydrolyze the thiopurine effector metabolites 6-thio-deoxyGTP (6-thio-dGTP) and 6-thio-GTP, thereby limiting the efficacy of thiopurines. In particular, increasing evidence suggests an association between the NUDT15 missense variant, R139C, and thiopurine sensitivity. In this study, we elucidated the role of NUDT15 and NUDT15 R139C in thiopurine metabolism. In vitro and cellular results argued that 6-thio-dGTP and 6-thio-GTP are favored substrates for NUDT15, a finding supported by a crystallographic determination of NUDT15 in complex with 6-thio-GMP. We found that NUDT15 R139C mutation did not affect enzymatic activity but instead negatively influenced protein stability, likely due to a loss of supportive intramolecular bonds that caused rapid proteasomal degradation in cells. Mechanistic investigations in cells indicated that NUDT15 ablation potentiated induction of the DNA damage checkpoint and cancer cell death by 6-thioguanine. Taken together, our results defined how NUDT15 limits thiopurine efficacy and how genetic ablation via the R139C missense mutation confers sensitivity to thiopurine treatment in patients. Cancer Res; 76(18); 5501-11. ©2016 AACR.
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Nicholas C K
authors.initials: NC
authors.lastname: Valerie
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Hagenkort
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Brent D G
authors.initials: BD
authors.lastname: Page
authors.affiliation: Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Masuyer
authors.affiliation: Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rehling
authors.affiliation: Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
authors.forename: Megan
authors.initials: M
authors.lastname: Carter
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Luka
authors.initials: L
authors.lastname: Bevc
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Patrick
authors.initials: P
authors.lastname: Herr
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Evert
authors.initials: E
authors.lastname: Homan
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Nina G
authors.initials: NG
authors.lastname: Sheppard
authors.affiliation: Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden. thomas.helleday@scilifelab.se stenmark@dbb.su.se annsofie.jemth@scilifelab.se.
authors.forename: Pål
authors.initials: P
authors.lastname: Stenmark
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden. thomas.helleday@scilifelab.se stenmark@dbb.su.se annsofie.jemth@scilifelab.se.
authors.forename: Ann-Sofie
authors.initials: AS
authors.lastname: Jemth
authors.affiliation: Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden. thomas.helleday@scilifelab.se stenmark@dbb.su.se annsofie.jemth@scilifelab.se.
authors.forename: Thomas
authors.initials: T
authors.lastname: Helleday
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000378:metabolism* / Q000494:pharmacology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D006801:Humans; D020125:Mutation, Missense; D055550:Protein Stability; D011755:Pyrophosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013866:Thioguanine / Q000378:metabolism* / Q000494:pharmacology*; D000096964:Nudix Hydrolases
chemical_list: D000964:Antimetabolites, Antineoplastic; D011755:Pyrophosphatases; D013866:Thioguanine; C543721:NUDT15 protein, human; D000096964:Nudix Hydrolases