Hydroxyurea induces chromosomal damage in G2 and enhances the clastogenic effect of mitomycin C in Fanconi anemia cells
Por:
Molina B., Marchetti F., Gómez L., Ramos S., Torres L., Ortiz R., Altamirano-Lozano M., Carnevale A., Frias S.
Publicada:
1 jun 2015
Resumen:
Fanconi's anemia (FA) is a recessive disease; 16 genes are currently recognized in FA. FA proteins participate in the FA/BRCA pathway that plays a crucial role in the repair of DNA damage induced by crosslinking compounds. Hydroxyurea (HU) is an agent that induces replicative stress by inhibiting ribonucleotide reductase (RNR), which synthesizes deoxyribonucleotide triphosphates (dNTPs) necessary for DNA replication and repair. HU is known to activate the FA pathway; however, its clastogenic effects are not well characterized. We have investigated the effects of HU treatment alone or in sequential combination with mitomycin-C (MMC) on FA patient-derived lymphoblastoid cell lines from groups FA-A, B, C, D1/BRCA2, and E and on lymphocytes from two unclassified FA patients. All FA cells showed a significant increase (P<0.05) in chromosomal aberrations following treatment with HU during the last 3 h before mitosis. Furthermore, when FA cells previously exposed to MMC were treated with HU, we observed an increase of MMC-induced DNA damage that was characterized by high occurrence of DNA breaks and a reduction in rejoined chromosomal aberrations. These findings show that exposure to HU during G2 induces chromosomal aberrations by a mechanism that is independent of its well-known role in replication fork stalling during S-phase and that HU interfered mainly with the rejoining process of DNA damage. We suggest that impaired oxidative stress response, lack of an adequate amount of dNTPs for DNA repair due to RNR inhibition, and interference with cell cycle control checkpoints underlie the clastogenic activity of HU in FA cells. © 2015 Wiley Periodicals, Inc.
Filiaciones:
Molina B.:
Laboratorio de Citogenética, Instituto Nacional de Pediatría, Mexico
Marchetti F.:
Lawrence Berkeley National Laboratory, Berkeley, CA, United States
Gómez L.:
Laboratorio de Citogenética, Instituto Nacional de Pediatría, Mexico
Ramos S.:
Laboratorio de Citogenética, Instituto Nacional de Pediatría, Mexico
Torres L.:
Laboratorio de Citogenética, Instituto Nacional de Pediatría, Mexico
Ortiz R.:
Laboratorio de Citometría de Flujo, Universidad Autónoma Metropolitana, Iztapalapa, Mexico
Altamirano-Lozano M.:
Univ Nacl Autonoma Mexico, Unidad Invest Genet & Toxicol UNIGEN, FES Zaragoza, Mexico City 04530, DF, Mexico
Carnevale A.:
Subdirección de Genómica Poblacional, Instituto Nacional de Medicina Genómica, Mexico
Frias S.:
Univ Nacl Autonoma Mexico, Dept Med Genom & Toxicol Ambiental, Inst Invest Biomed, Mexico City 04530, DF, Mexico
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