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Metabolism, mechanism of action and sensitivity profile of fluorocyclopentenylcytosine (RX-3117; TV-1360)
- Source :
- Peters, G J, Smid, K, Vecchi, L, Kathmann, I, Sarkisjan, D, Honeywell, R J, Losekoot, N, Ohne, O, Orbach, A, Blaugrund, E, Jeong, L S, Lee, Y B, Ahn, C H & Kim, D J 2013, ' Metabolism, mechanism of action and sensitivity profile of fluorocyclopentenylcytosine (RX-3117; TV-1360) ', Investigational New Drugs, vol. 31, no. 6, pp. 1444-1457 . https://doi.org/10.1007/s10637-013-0025-x, Investigational New Drugs, 31(6), 1444-1457. Kluwer Academic Publishers
- Publication Year :
- 2013
-
Abstract
- A novel cytidine analog fluorocyclopentenylcytosine (RX-3117; TV-1360) was characterized for its cytotoxicity in a 59-cell line panel and further characterized for cytotoxicity, metabolism and mechanism of action in 15 additional cancer cell lines, including gemcitabine-resistant variants. In both panels sensitivity varied 75-fold (IC50: 0.4- > 30 μM RX-3117). RX-3117 showed a different sensitivity profile compared to cyclopentenyl-cytosine (CPEC) and azacytidine, substrates for uridine-cytidine-kinase (UCK). Dipyridamole, an inhibitor of the equilibrative-nucleoside-transporter protected against RX-3117. Uridine and cytidine protected against RX-3117, but deoxycytidine (substrate for deoxycytidine-kinase [dCK]) not, although it protected against gemcitabine, demonstrating that RX-3117 is a substrate for UCK and not for dCK. UCK activity was abundant in all cell lines, including the gemcitabine-resistant variants. RX-3117 was a very poor substrate for cytidine deaminase (66,000-fold less than gemcitabine). RX-3117 was rapidly metabolised to its nucleotides predominantly the triphosphate, which was highest in the most sensitive cells (U937, A2780) and lowest in the least sensitive (CCRF-CEM). RX-3117 did not significantly affect cytidine and uridine nucleotide pools. Incorporation of RX-3117 into RNA and DNA was higher in sensitive A2780 and low in insensitive SW1573 cells. In sensitive U937 cells 1 μM RX-3117 resulted in 90 % inhibition of RNA synthesis but 100 μM RX-3117 was required in A2780 and CCRF-CEM cells. RX-3117 at IC50 values did not affect the integrity of RNA. DNA synthesis was completely inhibited in sensitive U937 cells at 1 μM, but in other cells even higher concentrations only resulted in a partial inhibition. At IC50 values RX-3117 downregulated the expression of DNA methyltransferase. In conclusion, RX-3117 showed a completely different sensitivity profile compared to gemcitabine and CPEC, its uptake is transporter dependent and is activated by UCK. RX-3117 is incorporated into RNA and DNA, did not affect RNA integrity, depleted DNA methyltransferase and inhibited RNA and DNA synthesis. Nucleotide formation is related with sensitivity.
- Subjects :
- Pharmacology
DNA synthesis
RNA
Cytidine
Antineoplastic Agents
Cytidine deaminase
DNA
Biology
Molecular biology
Uridine
Uridine kinase
chemistry.chemical_compound
Oncology
chemistry
Biochemistry
Cell Line, Tumor
Cytidine Deaminase
Humans
Pharmacology (medical)
Uridine Kinase
Nucleotide salvage
DNA Modification Methylases
Subjects
Details
- ISSN :
- 01676997
- Volume :
- 31
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- Investigational New Drugs
- Accession number :
- edsair.doi.dedup.....6007e50d218b698c53464fa972777893