CDD plays a pivotal role within the pyrimidine salvage pathway. In this study, a novel, rapid method for the identification of cell lines lacking functional cytidine deaminase was developed. This innovative method utilizes immunocytochemical detection of the product of 5-fluorocytidine deamination, 5-fluorouridine in cellular RNA, enabling the identification of these cells within two hours. The approach employs an anti-bromodeoxyuridine antibody that also specifically binds to 5-fluorouridine and its subsequent detection by a fluorescently labeled antibody. Our results also revealed a strong correlation between the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio and cytidine deaminase content. On the other hand, no correlation was observed between the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio and deoxycytidine monophosphate deaminase content. Similarly, no correlation was observed between this ratio and equilibrative nucleoside transporters 1 or 2. Finally, concentrative nucleoside transporters 1, 2, or 3 also do not correlate with the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio.

• Klíčová slova
• 5-fluorocytidine deamination, 5-fluorouridine, cytidine deaminase, equilibrative and concentrative nucleoside transporters,
• MeSH
• buněčné linie MeSH
• cytidin analogy a deriváty   metabolismus   MeSH
• cytidindeaminasa * metabolismus   nedostatek   genetika   MeSH
• lidé MeSH
• uridin analogy a deriváty   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 5-fluorouridine MeSH Prohlížeč
• cytidin MeSH
• cytidindeaminasa * MeSH
• uridin MeSH

Mismatched nucleobase uracil is commonly repaired through the base excision repair initiated by DNA uracil glycosylases. The data presented in this study strongly indicate that the nuclear uracil-N-glycosylase activity and nuclear protein content in human cell lines is highest in the S phase of the cell cycle and that its distribution kinetics partially reflect the DNA replication activity in replication foci. In this respect, the data demonstrate structural changes of the replication focus related to the uracil-N-glycosylase distribution several dozens of minutes before end of its replication. The analysis also showed that very popular synchronisation protocols based on the double thymidine block can result in changes in the UNG2 content and uracil excision rate. In response, we propose a new method for the description of the changes of the content and the activity of different cell components during cell cycle without the necessity to use synchronisation protocols.

• MeSH
• buněčný cyklus MeSH
• kinetika MeSH
• lidé MeSH
• oprava DNA MeSH
• replikace DNA * MeSH
• S fáze MeSH
• uracil-DNA-glykosidasa * metabolismus   MeSH
• uracil metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• uracil-DNA-glykosidasa * MeSH
• uracil MeSH

Deoxycytidine analogues (dCas) are widely used for the treatment of malignant diseases. They are commonly inactivated by cytidine deaminase (CDD), or by deoxycytidine monophosphate deaminase (dCMP deaminase). Additional metabolic pathways, such as phosphorylation, can substantially contribute to their (in)activation. Here, a new technique for the analysis of these pathways in cells is described. It is based on the use of 5-ethynyl 2'-deoxycytidine (EdC) and its conversion to 5-ethynyl 2'-deoxyuridine (EdU). Its use was tested for the estimation of the role of CDD and dCMP deaminase in five cancer and four non-cancer cell lines. The technique provides the possibility to address the aggregated impact of cytidine transporters, CDD, dCMP deaminase, and deoxycytidine kinase on EdC metabolism. Using this technique, we developed a quick and cheap method for the identification of cell lines exhibiting a lack of CDD activity. The data showed that in contrast to the cancer cells, all the non-cancer cells used in the study exhibited low, if any, CDD content and their cytidine deaminase activity can be exclusively attributed to dCMP deaminase. The technique also confirmed the importance of deoxycytidine kinase for dCas metabolism and indicated that dCMP deaminase can be fundamental in dCas deamination as well as CDD. Moreover, the described technique provides the possibility to perform the simultaneous testing of cytotoxicity and DNA replication activity.

• MeSH
• cytidin * metabolismus   MeSH
• cytidindeaminasa metabolismus   MeSH
• dCMP-deaminasa * MeSH
• deoxycytidin MeSH
• deoxycytidinkinasa genetika   metabolismus   MeSH
• metabolické sítě a dráhy MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytidin * MeSH
• cytidindeaminasa MeSH
• dCMP-deaminasa * MeSH
• deoxycytidin MeSH
• deoxycytidinkinasa MeSH

Base excision repair is one of the important DNA repair mechanisms in cells. The fundamental role in this complex process is played by DNA glycosylases. Here, we present a novel approach for the real-time measurement of uracil DNA glycosylase activity, which employs selected oligonucleotides immobilized on the surface of magnetic nanoparticles and Förster resonance energy transfer. We also show that the approach can be performed by surface plasmon resonance sensor technology. We demonstrate that the immobilization of oligonucleotides provides much more reliable data than the free oligonucleotides including molecular beacons. Moreover, our results show that the method provides the possibility to address the relationship between the efficiency of uracil DNA glycosylase activity and the arrangement of the used oligonucleotide probes. For instance, the introduction of the nick into oligonucleotide containing the target base (uracil) resulted in the substantial decrease of uracil DNA glycosylase activity of both the bacterial glycosylase and glycosylases naturally present in nuclear lysates.

• Klíčová slova
• Förster resonance energy transfer, base excision repair, immobilized oligonucleotides, surface plasmon resonance, uracil DNA glycosylase,
• MeSH
• buněčné jádro metabolismus   MeSH
• lidé MeSH
• magnetické nanočástice oxidů železa MeSH
• oligonukleotidové sondy chemie   metabolismus   MeSH
• oprava DNA MeSH
• rezonanční přenos fluorescenční energie MeSH
• uracil-DNA-glykosidasa metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• oligonukleotidové sondy MeSH
• uracil-DNA-glykosidasa MeSH