TY - JOUR
T1 - Mutagens interfere with microRNA maturation by inhibiting DICER. An in silico biology analysis
AU - Ligorio, Matteo
AU - Izzotti, Alberto
AU - Pulliero, Alessandra
AU - Arrigo, Patrizio
N1 - Funding Information:
This study was supported by Italian Association for cancer research (AIRC), grant number 8909 .
PY - 2011/12/1
Y1 - 2011/12/1
N2 - Exposure to environmental mutagens results in alteration of microRNA expression mainly oriented towards down-regulation, as typically observed in cigarette smoke. However, the molecular mechanism triggering this event is still unknown. To shed light on this issue, we developed an 'in silico' analysis testing 25 established environmental mutagens (polycyclic aromatic hydrocarbons, heterocyclic compounds, nitrosoamines, morpholine, ethylnitrosurea, benzene derivatives, hydroxyl amines, alkenes) for their potential to interfere with the function of DICER, the enzyme involved in the cytoplasmic phase of microRNA maturation. In order to analyse the binding affinity between DICER and each mutagen, the three-dimensional bioinformatic structures of DICER-RNase III domains and of mutagens have been constructed. The binding affinity of mutagens for each DICER's RNase III domain was estimated by calculating the global contact-energy and the number of intermolecular contacts. These two parameters reflect the stability of the DICER-mutagen complexes. All the 25 mutagens tested form stable complexes with DICER, 20 of which form a complex with DICER A domain, that is more stable than those formed by DICER with its natural substrate, i.e. double strand short RNAs. These mutagens are benzo(a)pyrene diol epoxide, nitroimidazoles, fluorenes, naphthalene, morpholine, stilbenes, hydroxylamines, fecapentenes. In the case of exposure to mutagen mixtures (benzo(a)pyrene-diolepoxide and 4-acetylaminostilbene), synergistic or less than addictive effects occur depending on the docking order of the compounds. A group of 8 mutagens with the highest ability to interfere with this DICER function, was identified by hierarchical cluster analysis. This group included 1-ethyl-1-nitrosourea and 4-nitrosomorpholine.Herein, presented data support the view that mutagens interfere with microRNA maturation by binding DICER. This finding sheds light on a new epigenetic mechanism exerted by environmental mutagens in inducing cell damage.
AB - Exposure to environmental mutagens results in alteration of microRNA expression mainly oriented towards down-regulation, as typically observed in cigarette smoke. However, the molecular mechanism triggering this event is still unknown. To shed light on this issue, we developed an 'in silico' analysis testing 25 established environmental mutagens (polycyclic aromatic hydrocarbons, heterocyclic compounds, nitrosoamines, morpholine, ethylnitrosurea, benzene derivatives, hydroxyl amines, alkenes) for their potential to interfere with the function of DICER, the enzyme involved in the cytoplasmic phase of microRNA maturation. In order to analyse the binding affinity between DICER and each mutagen, the three-dimensional bioinformatic structures of DICER-RNase III domains and of mutagens have been constructed. The binding affinity of mutagens for each DICER's RNase III domain was estimated by calculating the global contact-energy and the number of intermolecular contacts. These two parameters reflect the stability of the DICER-mutagen complexes. All the 25 mutagens tested form stable complexes with DICER, 20 of which form a complex with DICER A domain, that is more stable than those formed by DICER with its natural substrate, i.e. double strand short RNAs. These mutagens are benzo(a)pyrene diol epoxide, nitroimidazoles, fluorenes, naphthalene, morpholine, stilbenes, hydroxylamines, fecapentenes. In the case of exposure to mutagen mixtures (benzo(a)pyrene-diolepoxide and 4-acetylaminostilbene), synergistic or less than addictive effects occur depending on the docking order of the compounds. A group of 8 mutagens with the highest ability to interfere with this DICER function, was identified by hierarchical cluster analysis. This group included 1-ethyl-1-nitrosourea and 4-nitrosomorpholine.Herein, presented data support the view that mutagens interfere with microRNA maturation by binding DICER. This finding sheds light on a new epigenetic mechanism exerted by environmental mutagens in inducing cell damage.
KW - Bioinformatics
KW - DICER
KW - Epigenetic damage
KW - MicroRNA
KW - Mutagens
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U2 - 10.1016/j.mrfmmm.2011.07.020
DO - 10.1016/j.mrfmmm.2011.07.020
M3 - Article
C2 - 21889945
AN - SCOPUS:82755189462
SN - 0027-5107
VL - 717
SP - 116
EP - 128
JO - Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
JF - Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
IS - 1-2
ER -