title: Effects of intracellular calcium chelation and pifithrin-alpha on deoxynucleotide metabolism in human lymphocytes.
abstract: Previously, we have found that activation of deoxycytidine kinase elicited by various DNA-damaging chemical agents could be prevented by BAPTA-AM, a cell-permeable calcium chelator or by pifithrin-alpha, a pharmacological inhibitor of p53. Here, we show that stimulation of deoxycytidine kinase by UV-light also is calcium-dependent and pifithrin-alpha-sensitive in tonsillar lymphocytes, while thymidine kinase 1 activity is stabilised in the presence of BAPTA-AM. Importantly, both UV-irradiation and calcium chelation decreased the incorporation of labelled deoxycytidine and thymidine into DNA. Pifithrin-alpha dramatically reduced the labelling of both the nucleotide and DNA fractions, possibly due to inhibition of transmembrane nucleoside transport.
authors.affiliation: Institute of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary. spas@puskin.sote.hu
authors.forename: T
authors.initials: T
authors.lastname: Spasokoukotskaja
authors.forename: Z
authors.initials: Z
authors.lastname: Csapó
authors.forename: S
authors.initials: S
authors.lastname: Virga
authors.forename: M
authors.initials: M
authors.lastname: Sasvári-Székely
authors.forename: M
authors.initials: M
authors.lastname: Staub
authors.forename: G
authors.initials: G
authors.lastname: Keszler
mesh_terms: D052160:Benzothiazoles / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology*; D003842:Deoxycytidine Kinase / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D009711:Nucleotides / Q000737:chemistry / Q000378:metabolism*; D014050:Toluene / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D052160:Benzothiazoles; D002614:Chelating Agents; D009711:Nucleotides; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D014050:Toluene; D004533:Egtazic Acid; C121565:pifithrin; D003842:Deoxycytidine Kinase; D002118:Calcium