Involvement of DNA polymerase β in protection against the cytotoxicity of oxidative DNA damage

Horton, Julie K.; Baker, Audrey; Berg, Brian J. Vande; Sobol, Robert W.; Wilson, Samuel H.

doi:10.1016/s1568-7864(02)00008-3

Cited by 80 publications

(84 citation statements)

References 56 publications

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“…Specifically, we have reported on the extreme hypersensitivity of cells to MMS when combined with an inhibitor of PARP activity (8,13). Now we again demonstrate the tremendous potency of 4-AN in mouse fibroblasts ( Fig.…”

Section: Effect Of Parp Inhibition On Sensitivity To Dna-damagingsupporting

confidence: 62%

“…In addition, it is known that both wild-type and ␤-pol null cells can be extremely sensitized to MMS by the PARP inhibitors 3-AB and, in particular, 4-AN (8,13). Our observation that treatment of cells with MMS for 1 h along with exposure to 4-AN (10 M) for 24 h results in extreme sensitization to this methylating agent is illustrated in Fig.…”

Section: Effect Of Parp Inhibitors On Mms-induced Cytotoxicity Inmentioning

confidence: 55%

“…Singlenucleotide BER is still preferred (5), but the 5Ј dRP group is not an intermediate of repair, and there is no longer a requirement for the dRP lyase activity of ␤-pol. Less efficient repair of oxidized bases has been demonstrated in ␤-pol deficient cell extracts (6 -8), and ␤-pol null cells are hypersensitive to oxidative damage (8,9). Presumably it is the DNA synthesis activity of ␤-pol that is required under these circumstances.…”

mentioning

confidence: 99%

“…In addition, inhibition of PARP activity in mouse fibroblasts by 4-amino-1,8-naphthalimide (4-AN) or 3-aminobenzamide (3-AB) results in tremendous sensitization to MMS (8,13). The crystal structure of the catalytic domain of PARP-1 with 4-AN shows that the inhibitor binds to the nicotinamide subsite of the NAD ϩ binding pocket of the enzyme * The costs of publication of this article were defrayed in part by the payment of page charges.…”

mentioning

confidence: 99%

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Poly(ADP-ribose) Polymerase Activity Prevents Signaling Pathways for Cell Cycle Arrest after DNA Methylating Agent Exposure

Horton

Stefanick

Naron

et al. 2005

Journal of Biological Chemistry

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Mouse fibroblasts, deficient in DNA polymerase ␤, are hypersensitive to monofunctional DNA methylating agents such as methyl methanesulfonate (MMS). Both wild-type and, in particular, repair-deficient DNA polymerase ␤ null cells are highly sensitized to the cytotoxic effects of MMS by 4-amino-1,8-naphthalimide (4-AN), an inhibitor of poly(ADP-ribose) polymerase (PARP) activity. Experiments with synchronized cells suggest that exposure during S-phase of the cell cycle is required for the 4-AN effect. 4-AN elicits a similar extreme sensitization to the thymidine analog, 5-hydroxymethyl-2-deoxyuridine, implicating the requirement for an intermediate of DNA repair. In PARP-1-expressing fibroblasts treated with a combination of MMS and 4-AN, a complete inhibition of DNA synthesis is apparent after 4 h, and by 24 h, all cells are arrested in S-phase of the cell cycle. Continuous incubation with 4-AN is required to maintain the cell cycle arrest. Caffeine, an inhibitor of the upstream checkpoint kinases ATM (ataxia telangiectasia-mutated) and ATR (ATM and Rad3-related), has no effect on the early inhibition of DNA synthesis, but cells are no longer able to maintain the block after 8 h. Instead, the addition of caffeine leads to arrest of cells in G 2 /M rather than S-phase after 24 h. Analysis of signaling pathways in cell extracts reveals an activation of Chk1 after treatment with MMS and 4-AN, which can be suppressed by caffeine. Our results suggest that inhibition of PARP activity results in sensitization to MMS through maintenance of an ATR and Chk1-dependent S-phase checkpoint.Removal of unnatural bases or single base lesions from DNA is predominantly by a glycosylase-initiated base excision repair (BER) 1 pathway. Methylated bases are excised by N-methylpurine-DNA glycosylase, a monofunctional glycosylase. In the preferred "single-nucleotide" BER pathway, this is followed by strand cleavage on the 5Ј side of the sugar by apurinic/apyrimidinic endonuclease, gap filling and cleavage on the 3Ј side by the DNA synthesis and deoxyribose phosphate (dRP) lyase activities, respectively, of DNA polymerase ␤ (␤-pol), and finally sealing of the nick by a DNA ligase (1). The essential role of ␤-pol in this pathway has been established using extracts from wild-type and ␤-pol null mouse fibroblasts (2). The requirement for ␤-pol, more specifically the dRP lyase activity of ␤-pol, in protection of cells against the cytotoxicity of methyl DNA lesions, has been demonstrated by the hypersensitivity of ␤-pol null cells to the monofunctional methylating agent methyl methanesulfonate (MMS) (2, 3). It is thought that the MMS hypersensitivity phenotype of ␤-pol null cells reflects accumulation of cytotoxic repair intermediates, such as the 5Ј dRP group after removal of methylated bases from DNA (4).Repair of oxidative DNA damage occurs by an alternate sub-pathway of single-nucleotide BER utilizing bifunctional glycosylases that have an associated lyase activity that nicks the DNA strand 3Ј to the abasic site after base removal. Singlen...

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Section: Effect Of Parp Inhibition On Sensitivity To Dna-damagingsupporting

confidence: 62%

Section: Effect Of Parp Inhibitors On Mms-induced Cytotoxicity Inmentioning

confidence: 55%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Poly(ADP-ribose) Polymerase Activity Prevents Signaling Pathways for Cell Cycle Arrest after DNA Methylating Agent Exposure

Horton

Stefanick

Naron

et al. 2005

Journal of Biological Chemistry

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“…However, more recently it was discovered that pol β −/− mouse fibroblasts become increasingly sensitive to oxidative damaging agents (e.g., hydrogen peroxide and peroxynitrite) after time in culture. Late-passage cells demonstrate hypersensitivity when compared with the early-passage pol β null cells, and both early and late-passage wild-type fibroblasts [30] (Table 1). There are independent reports of pol β null cells demonstrating either hypersensitivity or a lack of hypersensitivity to hydrogen peroxide, but the age of the cells was not addressed [31,32].…”

Section: Mammalian Base Excision Repair (Ber)mentioning

confidence: 99%

Hypersensitivity phenotypes associated with genetic and synthetic inhibitor-induced base excision repair deficiency

Horton¹,

Wilson²

2007

DNA Repair

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Single-base lesions in DNA are repaired predominantly by base excision repair (BER). DNA polymerase β (pol β) is the polymerase of choice in the preferred single-nucleotide BER pathway. The characteristic phenotype of mouse fibroblasts with a deletion of the pol β gene is moderate hypersensitivity to monofunctional alkylating agents, e.g., methyl methanesulfonate (MMS). Increased sensitivity to MMS is also seen in the absence of pol β partner proteins XRCC1 and PARP-1, and under conditions where BER efficiency is reduced by synthetic inhibitors. PARP activity plays a major role in protection against MMS-induced cytotoxicity, and cells treated with a combination of non-toxic concentrations of MMS and a PARP inhibitor undergo cell cycle arrest and die by a Chk1-dependent apoptotic pathway. Since BER-deficient cells and tumors are similarly hypersensitive to the clinically used chemotherapeutic methylating agent temozolomide, modulation of DNA damage-induced cell signaling pathways, as well as BER, are attractive targets for potentiating chemotherapy.

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Intracellular Detection of Cytosine Incorporation in Genomic DNA by Using 5‐Ethynyl‐2′‐Deoxycytidine

et al. 2011

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5-Ethynyl-2′-deoxycytidine triphosphate (EdCTP) was synthesized as a probe to be used in conjunction with fluorescent labelling to facilitate the analysis of the in vivo dynamics of DNA-centered processes (DNA replication, repair and cytosine demethylation). Kinetic analysis showed that EdCTP is accepted as a substrate by Klenow exo- and DNA polymerase β. Incorporation of 5-ethynyl-2′-deoxycytidine (EdC) into DNA by these enzymes is at most modestly less efficient than native dC. EdC containing DNA was visualized using a click reaction with a fluorescent azide, following polymerase incorporation and T4 DNA ligase mediated ligation. Subsequent experiments in mouse male germ cells and zygotes demonstrated that EdC is a specific and reliable reporter of DNA replication in vivo.

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Involvement of DNA polymerase β in protection against the cytotoxicity of oxidative DNA damage

Cited by 80 publications

References 56 publications

Poly(ADP-ribose) Polymerase Activity Prevents Signaling Pathways for Cell Cycle Arrest after DNA Methylating Agent Exposure

Poly(ADP-ribose) Polymerase Activity Prevents Signaling Pathways for Cell Cycle Arrest after DNA Methylating Agent Exposure

Hypersensitivity phenotypes associated with genetic and synthetic inhibitor-induced base excision repair deficiency

Intracellular Detection of Cytosine Incorporation in Genomic DNA by Using 5‐Ethynyl‐2′‐Deoxycytidine

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