The nucleotidohydrolases DCTPP1 and dUTPase are involved in the cellular response to decitabine Requena Torres, Cristina Elena Pérez Moreno, Guiomar Horváth, András Vértessy, Beáta G. Ruiz Pérez, Luis Miguel González Pacanowska, Dolores Vidal, Antonio E. DCTPP1 XTP3-TPA dUTPase Nucleotide pool Decitabine This work was supported by the Ministerio de Economía y Competitividad (Plan Nacional de Investigación) [grant numbers SAF2011-27860 (to A.E.V.) and SAF2013-48999-R (to D.G.-P.)], Junta de Andalucía [grant numbers BIO-199 and P12-BIO-2059 (to D.G.-P.)], Hungarian National Research, Development and Innovation Office [grant numbers NK-84008 and K-109486], and the International Centre for Genetic Engineering and Biotechnology (ICGEB) [grant number CRP HUN14-01 (to B.G.V.)]. IMPACTO DE LAS ENFERMEDADES PROTOZOARIAS. ESTRATEGIAS EN EL DISEÑO RACIONAL DE FÁRMACOS. Instituto de Parasitología y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Científicas (CSIC), Armilla (Granada), 18016, Spain. Decitabine (5-aza-2'-deoxycytidine, aza-dCyd) is an anti-cancer drug used clinically for the treatment of myelodysplastic syndromes and acute myeloid leukaemia that can act as a DNA-demethylating or genotoxic agent in a dose-dependent manner. On the other hand, DCTPP1 (dCTP pyrophosphatase 1) and dUTPase are two 'house-cleaning' nucleotidohydrolases involved in the elimination of non-canonical nucleotides. In the present study, we show that exposure of HeLa cells to decitabine up-regulates the expression of several pyrimidine metabolic enzymes including DCTPP1, dUTPase, dCMP deaminase and thymidylate synthase, thus suggesting their contribution to the cellular response to this anti-cancer nucleoside. We present several lines of evidence supporting that, in addition to the formation of aza-dCTP (5-aza-2'-deoxycytidine-5'-triphosphate), an alternative cytotoxic mechanism for decitabine may involve the formation of aza-dUMP, a potential thymidylate synthase inhibitor. Indeed, dUTPase or DCTPP1 down-regulation enhanced the cytotoxic effect of decitabine producing an accumulation of nucleoside triphosphates containing uracil as well as uracil misincorporation and double-strand breaks in genomic DNA. Moreover, DCTPP1 hydrolyses the triphosphate form of decitabine with similar kinetic efficiency to its natural substrate dCTP and prevents decitabine-induced global DNA demethylation. The data suggest that the nucleotidohydrolases DCTPP1 and dUTPase are factors involved in the mode of action of decitabine with potential value as enzymatic targets to improve decitabine-based chemotherapy. 2024-09-27T10:41:28Z 2024-09-27T10:41:28Z 2016-08-30 journal article Published version: Requena Torres, Cristina Elena et al. The nucleotidohydrolases DCTPP1 and dUTPase are involved in the cellular response to decitabine. Biochem J . 2016 Sep 1;473(17):2635-43. https://doi.org/10.1042/BCJ20160302 https://hdl.handle.net/10481/95208 10.1042/BCJ20160302 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Portland Press