Abstract: Methylanthraniloyl derivatives of ATP and CDP were used in vitro as fluorescent probes for the donor-binding and acceptor-binding sites of human UMP-CMP kinase, a nucleoside salvage pathway kinase. Like all NMP kinases, UMP-CMP kinase binds the phosphodonor, usually ATP, and the NMP at different binding sites. The reaction results from an in-line phosphotransfer from the donor to the acceptor. The probe for the donor site was displaced by the bisubstrate analogs of the Ap5X series (where X =... Show More
Full-text available · Article · Aug 2007 · FEBS Journal
The irst phosphorylation is catalyzed by the cytosolic UMP-CMP kinase, producing CDVmonophosphate (CDVp) which is then phosphorylated by a nucleoside diphosphate kinase, pyruvate kinase or creatine kinase to the diphosphate form (CDVpp). The intracellular depot form of CDV, cidofovir monophosphocholine (CDVp-choline) is formed by choline-phosphate cytidylyltransferase . CDVpp is the active metabolite and can be incorporated into DNA instead of the natural substrate dCTP . The antiproliferative effects of CDV against HPV + cervical cancer cell lines were reported for the irst time in 1998 .
[Show abstract] [Hide abstract] ABSTRACT: Human papillomavirus (HPV) causes cervical cancer and a large fraction of head and neck squamous cell carcinomas (HNSCC). Cidofovir (CDV) proved efficacious in the treatment of several HPV-induced benign and malignant hyper proliferations. To provide a better insight into how CDV selectively eradicates transformed cells, HPV+ and HPV- cervical carcinoma and HNSCC cell lines were compared to normal cells for antiproliferative effects, CDV metabolism, drug incorporation into cellular DNA, and DNA damage. Incorporation of CDV into cellular DNA was higher in tumor cells than in normal cells and correlated with CDV antiproliferative effects, which were independent of HPV status. Increase in phospho-ATM levels was detected following CDV exposure and higher levels of γ-H2AX (a quantitative marker of double-strand breaks) were measured in tumor cells compared to normal cells. A correlation between DNA damage and CDV incorporation into DNA was found but not between DNA damage and CDV antiproliferative effects. These data indicate that CDV antiproliferative effects result from incorporation of the drug into DNA causing DNA damage. However, the anti-tumor effects of CDV cannot be exclusively ascribed to DNA damage. Furthermore, CDV can be considered a promising broad spectrum anti-cancer agent, not restricted to HPV+ lesions.