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XPD-dependent activation of apoptosis in response to triplex-induced DNA damage
DNA sequences capable of forming triplexes are prevalent in the human genome and have been found to be intrinsically mutagenic. Consequently, a balance between DNA repair and apoptosis is critical to counteract their effect on genomic integrity. Using triplex-forming oligonucleotides to syntheticall...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3799437/ https://www.ncbi.nlm.nih.gov/pubmed/23913414 http://dx.doi.org/10.1093/nar/gkt670 |
Sumario: | DNA sequences capable of forming triplexes are prevalent in the human genome and have been found to be intrinsically mutagenic. Consequently, a balance between DNA repair and apoptosis is critical to counteract their effect on genomic integrity. Using triplex-forming oligonucleotides to synthetically create altered helical distortions, we have determined that pro-apoptotic pathways are activated by the formation of triplex structures. Moreover, the TFIIH factor, XPD, occupies a central role in triggering apoptosis in response to triplex-induced DNA strand breaks. Here, we show that triplexes are capable of inducing XPD-independent double strand breaks, which result in the formation of γH2AX foci. XPD was subsequently recruited to the triplex-induced double strand breaks and co-localized with γH2AX at the damage site. Furthermore, phosphorylation of H2AX tyrosine 142 was found to stimulate the signaling pathway of XPD-dependent apoptosis. We suggest that this mechanism may play an active role in minimizing genomic instability induced by naturally occurring noncanonical structures, perhaps protecting against cancer initiation. |
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