title: Dr Jekyll and Mr Hyde: a strange case of 5-ethynyl-2'-deoxyuridine and 5-ethynyl-2'-deoxycytidine.
abstract: 5-Ethynyl-2'-deoxyuridine (EdU) and 5-ethynyl-2'-deoxycytidine (EdC) are mainly used as markers of cellular replicational activity. Although EdU is employed as a replicational marker more frequently than EdC, its cytotoxicity is commonly much higher than the toxicity of EdC. To reveal the reason of the lower cytotoxicity of EdC, we performed a DNA analysis of five EdC-treated human cell lines. Surprisingly, not a single one of the tested cell lines contained a detectable amount of EdC in their DNA. Instead, the DNA of all the cell lines contained EdU. The content of incorporated EdU differed in particular cells and EdC-related cytotoxicity was directly proportional to the content of EdU. The results of experiments with the targeted inhibition of the cytidine deaminase (CDD) and dCMP deaminase activities indicated that the dominant role in the conversion pathway of EdC to EdUTP is played by CDD in HeLa cells. Our results also showed that the deamination itself was not able to effectively prevent the conversion of EdC to EdCTP, the conversion of EdC to EdCTP occurs with much lesser effectivity than the conversion of EdU to EdUTP and the EdCTP is not effectively recognized by the replication complex as a substrate for the synthesis of nuclear DNA.
authors.affiliation: Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Olomouc 77900, Czech Republic anna.ligasova@upol.cz.
authors.forename: Anna
authors.initials: A
authors.lastname: Ligasová
authors.affiliation: Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, v.v.i., Prague 16610, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Liboska
authors.affiliation: Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Olomouc 77900, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Friedecký
authors.affiliation: Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Olomouc 77900, Czech Republic.
authors.forename: Kateřina
authors.initials: K
authors.lastname: Mičová
authors.affiliation: Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Olomouc 77900, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Adam
authors.affiliation: Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Olomouc 77900, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Oždian
authors.affiliation: Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, v.v.i., Prague 16610, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Rosenberg
authors.affiliation: Institute of Molecular and Translational Medicine, Palacký University in Olomouc, Olomouc 77900, Czech Republic karel.koberna@upol.cz.
authors.forename: Karel
authors.initials: K
authors.lastname: Koberna
mesh_terms: D000906:Antibodies / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D016923:Cell Death; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003564:Cytidine Deaminase / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004261:DNA Replication; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000378:metabolism*; D003857:Deoxyuridine / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D055442:Metabolome; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: C000611377:5-ethynyl-2'-deoxycytidine; D000906:Antibodies; D034741:RNA, Small Interfering; D003841:Deoxycytidine; D004247:DNA; D003564:Cytidine Deaminase; D001973:Bromodeoxyuridine; C031086:5-ethynyl-2'-deoxyuridine; D003857:Deoxyuridine
keywords: 5-ethynyl-2′-deoxycytidine; 5-ethynyl-2′-deoxyuridine; DNA replication; cytidine deaminase; dCMP deaminase