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Activating mutations in the cytosolic 5'-nucleotidase II gene NT5C2 drive resistance to 6-mercaptopurine in acute lymphoblastic leukemia. Here we demonstrate that constitutively active NT5C2 mutations K359Q and L375F reconfigure the catalytic center for substrate access and catalysis in the absence of allosteric activator. In contrast, most relapse-associated mutations, which involve the arm segment and residues along the surface of the inter-monomeric cavity, disrupt a built-in switch-off mechanism responsible for turning off NT5C2. In addition, we show that the C-terminal acidic tail lost in the Q523X mutation functions to restrain NT5C2 activation. These results uncover dynamic mechanisms of enzyme regulation targeted by chemotherapy resistance-driving NT5C2 mutations, with important implications for the development of NT5C2 inhibitor therapies.
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http://dx.doi.org/10.1016/j.ccell.2018.06.003 | DOI Listing |
Int J Mol Sci
July 2025
Unidad de Investigación Médica en Genética Humana, Hospital de Pediatría "Dr. Silvestre Frenk Freund", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico.
B-lineage acute lymphoblastic leukemia (B-ALL) is classified into more than 20 molecular subtypes, and next-generation sequencing has facilitated the identification of these with high sensitivity. Bulk RNA-seq analysis of bone marrow was realized to identify molecular subtypes in Mexican pediatric patients with B-ALL. High hyperdiploidy (27.
View Article and Find Full Text PDFHemasphere
May 2025
Institut d'Investigació contra la Leucemia Josep Carreras (IJC), Campus ICO-Germans Trias i Pujol Universitat Autònoma de Barcelona Badalona Spain.
Relapse is the main cause of treatment failure in T-cell acute lymphoblastic leukemia (T-ALL). Despite this, data from adult T-ALL patients treated with specific chemotherapeutic regimens that examine predictive markers and describe relapse mechanisms are scarce. In this study, we studied 74 paired diagnosis-relapse samples from 37 patients homogeneously treated with three consecutive measurable residual disease-oriented trials to identify genetic determinants involved in relapse in adult T-ALL.
View Article and Find Full Text PDFMod Pathol
June 2025
HCEMM-SE Molecular Oncohematology Research Group, Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary; MTA-SE "Lendület" Molecular Oncohematology Research Group, Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest,
Risk-adapted treatment protocols conferred remarkable improvement in the survival rates of pediatric acute lymphoblastic leukemia/lymphoma (ALL/LBL). Nevertheless, clinical management is still challenging in certain molecular subgroups and in the presence of alterations associated with an increased rate of relapse. In this study, disease-relevant genomic and transcriptomic profiles were established in a prospective, multicenter, real-world cohort involving 192 children diagnosed with ALL/LBL.
View Article and Find Full Text PDFJ Biol Chem
March 2025
Université catholique de Louvain (UCLouvain) and de Duve Institute (DDUV), Brussels, Belgium. Electronic address:
Obesity and type 2 diabetes (T2D)-linked hyperglycemia, along with their associated complications, have reached pandemic proportions, constituting a major public health issue. Genetic deletion or pharmacological inhibition of purine nucleotide-metabolizing enzymes has emerged as a potential strategy for treating diseases. We previously showed that cytosolic 5'-nucleotidase II (NT5C2)-deficient mice were protected against high-fat diet (HFD)-induced insulin resistance.
View Article and Find Full Text PDFPediatr Blood Cancer
February 2025
Pediatric Hematology-Oncology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Introduction: Digital polymerase chain reaction (PCR) studies for clonal disease monitoring in B-acute lymphoblastic leukemia patients are currently limited due to the heterogeneous nature of mutations, which limit cost-effective assay designs.
Materials And Methods: In this study, 70 samples (14 relapse and 56 sequential therapy samples) were tested for 13 recurrent mutations identified on deep sequencing in our published cohort (KRAS, NRAS, NT5C2, PMS2, UHRF1, KMT2D, and TP53 genes) via a novel triplex digital PCR assay.
Results And Discussion: A total of seven major clones of NRAS [five] and NT5C2 [two] were noted in six out of 14 (43%) relapse patients, accounting for 44% of early relapses.