scholarly journals Search for DNA damage by human alkyladenine DNA glycosylase involves early intercalation by an aromatic residue

2017 ◽  
Vol 292 (39) ◽  
pp. 16070-16080 ◽  
Author(s):  
Jenna M. Hendershot ◽  
Patrick J. O'Brien
Biochemistry ◽  
2008 ◽  
Vol 47 (44) ◽  
pp. 11434-11445 ◽  
Author(s):  
Mark Hedglin ◽  
Patrick J. O’Brien

2013 ◽  
Vol 288 (34) ◽  
pp. 24550-24559 ◽  
Author(s):  
Mark Hedglin ◽  
Yaru Zhang ◽  
Patrick J. O'Brien

Talanta ◽  
2019 ◽  
Vol 194 ◽  
pp. 846-851 ◽  
Author(s):  
Lili Wang ◽  
Huige Zhang ◽  
Yi Xie ◽  
Hongli Chen ◽  
Cuiling Ren ◽  
...  

2002 ◽  
Vol 49 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Janusz Błasiak ◽  
Ewa Gloc ◽  
Mariusz Warszawski

Idarubicin is an anthracycline antibiotic used in cancer therapy. Mitoxantrone is an anthracycline analog with presumed better antineoplastic activity and lesser toxicity. Using the alkaline comet assaywe showed that the drugs at 0.01-10 microM induced DNA damage in normal human lymphocytes. The effect induced by idarubicin was more pronounced than by mitoxantrone (P < 0.001). The cells treated with mitoxantrone at 1 microM were able to repair damage to their DNA within a 30-min incubation, whereas the lymphocytes exposed to idarubicin needed 180 min. Since anthracyclines are known to produce free radicals, we checked whether reactive oxygen species might be involved in the observed DNA damage. Catalase, an enzyme inactivating hydrogen peroxide, decreased the extent of DNA damage induced by idarubicin, but did not affect the extent evoked by mitoxantrone. Lymphocytes exposed to the drugs and treated with endonuclease III or formamidopyrimidine-DNA glycosylase (Fpg), enzymes recognizing and nicking oxidized bases, displayed a higher level of DNA damage than the untreated ones. 3-Methyladenine-DNA glycosylase II (AlkA), an enzyme recognizing and nicking mainly methylated bases in DNA, increased the extent of DNA damage caused by idarubicin, but not that induced by mitoxantrone. Our results indicate that the induction of secondary malignancies should be taken into account as side effects of the two drugs. Direct strand breaks, oxidation and methylation of the DNA bases can underlie the DNA-damaging effect of idarubicin, whereas mitoxantrone can induce strand breaks and modification of the bases, including oxidation. The observed in normal lymphocytes much lesser genotoxicity of mitoxantrone compared to idarubicin should be taken into account in planning chemotherapeutic strategies.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nicola P. Montaldo ◽  
Diana L. Bordin ◽  
Alessandro Brambilla ◽  
Marcel Rösinger ◽  
Sarah L. Fordyce Martin ◽  
...  

AbstractBase excision repair (BER) initiated by alkyladenine DNA glycosylase (AAG) is essential for removal of aberrantly methylated DNA bases. Genome instability and accumulation of aberrant bases accompany multiple diseases, including cancer and neurological disorders. While BER is well studied on naked DNA, it remains unclear how BER efficiently operates on chromatin. Here, we show that AAG binds to chromatin and forms complex with RNA polymerase (pol) II. This occurs through direct interaction with Elongator and results in transcriptional co-regulation. Importantly, at co-regulated genes, aberrantly methylated bases accumulate towards the 3′end in regions enriched for BER enzymes AAG and APE1, Elongator and active RNA pol II. Active transcription and functional Elongator are further crucial to ensure efficient BER, by promoting AAG and APE1 chromatin recruitment. Our findings provide insights into genome stability maintenance in actively transcribing chromatin and reveal roles of aberrantly methylated bases in regulation of gene expression.


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