Chemical Incorporation of Chain-Terminating Nucleoside Analogs as 3′-Blocking DNA Damage and Their Removal by Human ERCC1-XPF Endonuclease

Yamamoto, Junpei; Takahata, Chiaki; Kuraoka, Isao; Hirota, Kouji; Iwai, Shigenori

doi:10.3390/molecules21060766

Cited by 4 publications

(2 citation statements)

References 29 publications

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“…The oligonucleotides, d(TCCGTTGAAGCCTGC TTT)X, where X represents carbovir, or lamivudine, were chemically synthesized as described previously [ 42 ]. The 3′ Ara-C docking oligo was previously used [ 31 ].…”

Section: Methodsmentioning

confidence: 99%

The dominant role of proofreading exonuclease activity of replicative polymerase ε in cellular tolerance to cytarabine (Ara-C)

et al. 2017

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Chemotherapeutic nucleoside analogs, such as Ara-C, 5-Fluorouracil (5-FU) and Trifluridine (FTD), are frequently incorporated into DNA by the replicative DNA polymerases. However, it remains unclear how this incorporation kills cycling cells. There are two possibilities: Nucleoside analog triphosphates inhibit the replicative DNA polymerases, and/or nucleotide analogs mis-incorporated into genomic DNA interfere with the next round of DNA synthesis as replicative DNA polymerases recognize them as template DNA lesions, arresting synthesis. To address the first possibility, we selectively disrupted the proofreading exonuclease activity of DNA polymerase ε (Polε), the leading-strand replicative polymerase in avian DT40 and human TK6 cell lines. To address the second, we disrupted RAD18, a gene involved in translesion DNA synthesis, a mechanism that relieves stalled replication. Strikingly, POLE1exo−/− cells, but not RAD18−/− cells, were hypersensitive to Ara-C, while RAD18−/− cells were hypersensitive to FTD. gH2AX focus formation following a pulse of Ara-C was immediate and did not progress into the next round of replication, while gH2AX focus formation following a pulse of 5-FU and FTD was delayed to the next round of replication. Biochemical studies indicate that human proofreading-deficient Polε-exo− holoenzyme incorporates Ara-CTP, but subsequently extend from this base several times less efficiently than from intact nucleotides. Together our results suggest that Ara-C acts by blocking extension of the nascent DNA strand and is counteracted by the proofreading activity of Polε, while 5-FU and FTD are efficiently incorporated but act as replication fork blocks in the subsequent S phase, which is counteracted by translesion synthesis.

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Section: Methodsmentioning

confidence: 99%

The dominant role of proofreading exonuclease activity of replicative polymerase ε in cellular tolerance to cytarabine (Ara-C)

et al. 2017

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“…Chain-terminating nucleoside analogs (CTNAs) lack a 3′-OH group and thus block DNA synthesis after being incorporated into DNA. These CTNAs are extensively used as anti-viral and anti-cancer agents especially in treating HIV and adult T-cell leukemia (ATL) respectively ( 43 ). TDP1 repairs nuclear and mitochondrial DNA damage induced by CTNAs including acyclovir (ACV), cytarabine (Ara-C), zidovudine (AZT) and zalcitabine (ddC) (Figure 3G – J ) ( 44 ).…”

Section: Tyrosyl–dna Phosphodiesterase 1 (Tdp1)mentioning

confidence: 99%

Tyrosyl–DNA phosphodiesterases: rescuing the genome from the risks of relaxation

Kawale

Povirk

2017

Nucleic Acids Research

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Tyrosyl–DNA Phosphodiesterases 1 (TDP1) and 2 (TDP2) are eukaryotic enzymes that clean-up after aberrant topoisomerase activity. While TDP1 hydrolyzes phosphotyrosyl peptides emanating from trapped topoisomerase I (Top I) from the 3′ DNA ends, topoisomerase 2 (Top II)-induced 5′-phosphotyrosyl residues are processed by TDP2. Even though the canonical functions of TDP1 and TDP2 are complementary, they exhibit little structural or sequence similarity. Homozygous mutations in genes encoding these enzymes lead to the development of severe neurodegenerative conditions due to the accumulation of transcription-dependent topoisomerase cleavage complexes underscoring the biological significance of these enzymes in the repair of topoisomerase–DNA lesions in the nervous system. TDP1 can promiscuously process several blocked 3′ ends generated by DNA damaging agents and nucleoside analogs in addition to hydrolyzing 3′-phosphotyrosyl residues. In addition, deficiency of these enzymes causes hypersensitivity to anti-tumor topoisomerase poisons. Thus, TDP1 and TDP2 are promising therapeutic targets and their inhibitors are expected to significantly synergize the effects of current anti-tumor therapies including topoisomerase poisons and other DNA damaging agents. This review covers the structural aspects, biology and regulation of these enzymes, along with ongoing developments in the process of discovering safe and effective TDP inhibitors.

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PrimPol-mediated repriming elicits gap-filling by template switching and promotes cellular tolerance to cidofovir

Washif,

Kawasumi,

Hirota

2025

DNA Repair

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Chemical Incorporation of Chain-Terminating Nucleoside Analogs as 3′-Blocking DNA Damage and Their Removal by Human ERCC1-XPF Endonuclease

Cited by 4 publications

References 29 publications

The dominant role of proofreading exonuclease activity of replicative polymerase ε in cellular tolerance to cytarabine (Ara-C)

The dominant role of proofreading exonuclease activity of replicative polymerase ε in cellular tolerance to cytarabine (Ara-C)

Tyrosyl–DNA phosphodiesterases: rescuing the genome from the risks of relaxation

PrimPol-mediated repriming elicits gap-filling by template switching and promotes cellular tolerance to cidofovir

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