title: The pivotal role of uridine-cytidine kinases in pyrimidine metabolism and activation of cytotoxic nucleoside analogues in neuroblastoma.
abstract: Uridine-cytidine kinase (UCK) catalyzes the phosphorylation of uridine and cytidine as well as the pharmacological activation of several cytotoxic pyrimidine ribonucleoside analogues. In this study, we investigated the functional role of two isoforms of UCK in neuroblastoma cell lines. Analysis of mRNA coding for UCK1 and UCK2 showed that UCK2 is the most abundantly expressed UCK in a panel of neuroblastoma cell lines. Transient and stable overexpression of UCK2 in neuroblastoma cells increased the metabolism of uridine and cytidine as well as the cytotoxicity of 3-deazauridine. Knockdown of endogenous UCK2 as well as overexpression of UCK1 resulted in decreased metabolism of uridine and cytidine and protected the neuroblastoma cells from 3-deazauridine-induced toxicity. Subcellular localization studies showed that UCK1-GFP and UCK2-GFP were localized in the cell nucleus and cytosol, respectively. However, co-expression of UCK1 with UCK2 resulted in a nuclear localization of UCK2 instead of its normal cytosolic localization, thereby impairing its normal function. The physical association of UCK1 and UCK2 was further demonstrated through pull-down analysis using his-tagged UCK. The discovery that UCK2 is highly expressed in neuroblastoma opens the possibility for selectively targeting neuroblastoma cells using UCK2-dependent pyrimidine analogues, while sparing normal tissues.
authors.affiliation: Academic Medical Center, University of Amsterdam, Emma Children's Hospital, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Amsterdam, The Netherlands. Electronic address: a.b.vankuilenburg@amc.uva.nl.
authors.forename: André B P
authors.initials: AB
authors.lastname: van Kuilenburg
authors.affiliation: Academic Medical Center, University of Amsterdam, Emma Children's Hospital, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Amsterdam, The Netherlands.
authors.forename: Rutger
authors.initials: R
authors.lastname: Meinsma
mesh_terms: D000970:Antineoplastic Agents / Q000378:metabolism / Q000627:therapeutic use; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003562:Cytidine / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D000071447:N-Myc Proto-Oncogene Protein / Q000235:genetics; D009447:Neuroblastoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D009705:Nucleosides / Q000378:metabolism* / Q000633:toxicity; D010766:Phosphorylation; D011743:Pyrimidines / Q000378:metabolism* / Q000627:therapeutic use; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D014529:Uridine / Q000378:metabolism; D014541:Uridine Kinase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009705:Nucleosides; D011743:Pyrimidines; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011993:Recombinant Fusion Proteins; D003562:Cytidine; C483834:UCK2 protein, human; D014541:Uridine Kinase; D014529:Uridine
keywords: Cytotoxicity; Metabolism; Neuroblastoma; Nucleoside analogues; Uridine-cytidine kinase