scholarly journals X-ray repair cross-complementing protein 1 (XRCC1) loss promotes β-lapachone –induced apoptosis in pancreatic cancer cells

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yansong Zheng ◽  
Hengce Zhang ◽  
Yueting Guo ◽  
Yuan Chen ◽  
Hanglong Chen ◽  
...  
Keyword(s):  
Cell Death ◽  
Excision Repair ◽  
Critical Role ◽  
Relative Survival ◽  
Dna Lesions ◽  
Dna Double Strand Breaks ◽  
Γh2ax Foci ◽  
Pancreatic Cancer Cells ◽  
Base Excision ◽  
Induced Apoptosis

Abstract Background β-lapachone (β-lap), the NQO1 bioactivatable drug, is thought to be a promising anticancer agent. However, the toxic side effects of β-lap limit the drug use, highlighting the need for a thorough understanding of β-lap’s mechanism of action. β-lap undergoes NQO1-dependent futile redox cycling, generating massive ROS and oxidative DNA lesions, leading to cell death. Thus, base excision repair (BER) pathway is an important resistance factor. XRCC1, a scaffolding component, plays a critical role in BER. Methods We knocked down XRCC1 expression by using pLVX-shXRCC1 in the MiaPaCa2 cells and BxPC3 cells and evaluated β-lap-induced DNA lesions by γH2AX foci formation and alkaline comet assay. The cell death induced by XRCC1 knockdown + β-lap treatment was analysed by relative survival, flow cytometry and Western blotting analysis. Results We found that knockdown of XRCC1 significantly increased β-lap-induced DNA double-strand breaks, comet tail lengths and cell death in PDA cells. Furthermore, we observed combining XRCC1 knockdown with β-lap treatment switched programmed necrosis with β-lap monotherapy to caspase-dependent apoptosis. Conclusions These results indicate that XRCC1 is involved in the repair of β-lap-induced DNA damage, and XRCC1 loss amplifies sensitivity to β-lap, suggesting targeting key components in BER pathways may have the potential to expand use and efficacy of β-lap for gene-based therapy.

scholarly journals The Role of Base Excision Repair in the Sensitivity and Resistance to Temozolomide-Mediated Cell Death

2005 ◽  
Vol 65 (14) ◽  
pp. 6394-6400 ◽  
Author(s):  
Ram N. Trivedi ◽  
Karen H. Almeida ◽  
Jamie L. Fornsaglio ◽  
Sandra Schamus ◽  
Robert W. Sobol
Keyword(s):  
Cell Death ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Base Excision

scholarly journals Alleviation of C⋅C Mismatches in DNA by the Escherichia coli Fpg Protein

2021 ◽  
Vol 12 ◽  
Author(s):  
Almaz Nigatu Tesfahun ◽  
Marina Alexeeva ◽  
Miglė Tomkuvienė ◽  
Aysha Arshad ◽  
Prashanna Guragain ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Excision Repair ◽  
Dna Lesions ◽  
Base Pairs ◽  
E Coli ◽  
Thymine Glycol ◽  
Base Excision ◽  
The Cost ◽  
Primary Substrate

DNA polymerase III mis-insertion may, where not corrected by its 3′→ 5′ exonuclease or the mismatch repair (MMR) function, result in all possible non-cognate base pairs in DNA generating base substitutions. The most thermodynamically unstable base pair, the cytosine (C)⋅C mismatch, destabilizes adjacent base pairs, is resistant to correction by MMR in Escherichia coli, and its repair mechanism remains elusive. We present here in vitro evidence that C⋅C mismatch can be processed by base excision repair initiated by the E. coli formamidopyrimidine-DNA glycosylase (Fpg) protein. The kcat for C⋅C is, however, 2.5 to 10 times lower than for its primary substrate 8-oxoguanine (oxo8G)⋅C, but approaches those for 5,6-dihydrothymine (dHT)⋅C and thymine glycol (Tg)⋅C. The KM values are all in the same range, which indicates efficient recognition of C⋅C mismatches in DNA. Fpg activity was also exhibited for the thymine (T)⋅T mismatch and for N4- and/or 5-methylated C opposite C or T, Fpg activity being enabled on a broad spectrum of DNA lesions and mismatches by the flexibility of the active site loop. We hypothesize that Fpg plays a role in resolving C⋅C in particular, but also other pyrimidine⋅pyrimidine mismatches, which increases survival at the cost of some mutagenesis.

scholarly journals Oxygen-Dependent Accumulation of Purine DNA Lesions in Cockayne Syndrome Cells

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1671 ◽  
Author(s):  
Marios G. Krokidis ◽  
Mariarosaria D’Errico ◽  
Barbara Pascucci ◽  
Eleonora Parlanti ◽  
Annalisa Masi ◽  
...  
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Excision Repair ◽  
Enzymatic Digestion ◽  
Cockayne Syndrome ◽  
Dna Lesions ◽  
Premature Aging ◽  
Neurological Features ◽  
Oxygen Tensions ◽  
Base Excision

Cockayne Syndrome (CS) is an autosomal recessive neurodegenerative premature aging disorder associated with defects in nucleotide excision repair (NER). Cells from CS patients, with mutations in CSA or CSB genes, present elevated levels of reactive oxygen species (ROS) and are defective in the repair of a variety of oxidatively generated DNA lesions. In this study, six purine lesions were ascertained in wild type (wt) CSA, defective CSA, wtCSB and defective CSB-transformed fibroblasts under different oxygen tensions (hyperoxic 21%, physioxic 5% and hypoxic 1%). In particular, the four 5′,8-cyclopurine (cPu) and the two 8-oxo-purine (8-oxo-Pu) lesions were accurately quantified by LC-MS/MS analysis using isotopomeric internal standards after an enzymatic digestion procedure. cPu levels were found comparable to 8-oxo-Pu in all cases (3–6 lesions/106 nucleotides), slightly increasing on going from hyperoxia to physioxia to hypoxia. Moreover, higher levels of four cPu were observed under hypoxia in both CSA and CSB-defective cells as compared to normal counterparts, along with a significant enhancement of 8-oxo-Pu. These findings revealed that exposure to different oxygen tensions induced oxidative DNA damage in CS cells, repairable by NER or base excision repair (BER) pathways. In NER-defective CS patients, these results support the hypothesis that the clinical neurological features might be connected to the accumulation of cPu. Moreover, the elimination of dysfunctional mitochondria in CS cells is associated with a reduction in the oxidative DNA damage.

scholarly journals Formation of cytosine glycol and 5,6-dihydroxycytosine in deoxyribonucleic acid on treatment with osmium tetroxide

1986 ◽  
Vol 235 (2) ◽  
pp. 531-536 ◽  
Author(s):  
M Dizdaroglu ◽  
E Holwitt ◽  
M P Hagan ◽  
W F Blakely
Keyword(s):  
Dna Repair ◽  
Formic Acid ◽  
Excision Repair ◽  
Dna Lesions ◽  
Gas Chromatography Mass Spectrometry ◽  
Dna Glycosylases ◽  
Thymine Glycol ◽  
Repair Enzymes ◽  
Base Excision

OsO4 selectively forms thymine glycol lesions in DNA. In the past, OsO4-treated DNA has been used as a substrate in studies of DNA repair utilizing base-excision repair enzymes such as DNA glycosylases. There is, however, no information available on the chemical identity of other OsO4-induced base lesions in DNA. A complete knowledge of such DNA lesions may be of importance for repair studies. Using a methodology developed recently for characterization of oxidative base damage in DNA, we provide evidence for the formation of cytosine glycol and 5,6-dihydroxycytosine moieties, in addition to thymine glycol, in DNA on treatment with OsO4. For this purpose, samples of OsO4-treated DNA were hydrolysed with formic acid, then trimethylsilylated and analysed by capillary gas chromatography-mass spectrometry. In addition to thymine glycol, 5-hydroxyuracil (isobarbituric acid), 5-hydroxycytosine and 5,6-dihydroxyuracil (isodialuric acid or dialuric acid) were identified in OsO4-treated DNA. It is suggested that 5-hydroxyuracil was formed by formic acid-induced deamination and dehydration of cytosine glycol, which was the actual oxidation product of the cytosine moiety in DNA. 5-Hydroxycytosine obviously resulted from dehydration of cytosine glycol, and 5,6-dihydroxyuracil from deamination of 5,6-dihydroxycytosine. This scheme was supported by the presence of 5-hydroxyuracil, uracil glycol and 5,6-dihydroxyuracil in OsO4-treated cytosine. Treatment of OsO4-treated cytosine with formic acid caused the complete conversion of uracil glycol into 5-hydroxyuracil. The implications of these findings relative to studies of DNA repair are discussed.

141 INDICATIONS FOR DNA DOUBLE-STRAND BREAK REPAIR IN EARLY BOVINE EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 188
Author(s):  
A. Brero ◽  
D. Koehler ◽  
T. Cremer ◽  
E. Wolf ◽  
V. Zakhartchenko
Keyword(s):  
Dna Repair ◽  
Homologous Recombination ◽  
Strand Break ◽  
Dna Lesions ◽  
Homologous Recombination Repair ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Male And Female ◽  
Γh2ax Foci ◽  
Recombination Repair

DNA double-strand breaks (DSBs) are considered the most severe type of DNA lesions, because such lesions, if unrepaired, lead to a loss of genome integrity. Soon after induction of DSBs, chromatin surrounding the damage is modified by phosphorylation of the histone variant H2AX, generating so-called γH2AX, which is a hallmark of DSBs (Takahashi et al. 2005 Cancer Lett. 229, 171–179). γH2AX appears to be a signal for the recruitment of proteins constituting the DNA repair machinery. Depending on the type of damage and the cell cycle stage of the affected cell, DSBs are repaired either by nonhomologous end joining or by homologous recombination using the sister chromatid DNA as template (Hoeijmakers 2001 Nature 411, 366–374). We used immunofluorescence to analyze chromatin composition during bovine development and found γH2AX foci in both male and female pronuclei of IVF embryos. The number and size of foci varied considerably between embryos and between the male and female pronuclei. To test whether the observed γH2AX foci represented sites of active DNA repair, we co-stained IVF zygotes for γH2AX and 3 different proteins involved in homologous recombination repair of DSBs: NBS1 (phosphorylated at amino acid serine 343), 53BP1, and Rad51. We found co-localization of γH2AX foci with phosphorylated NBS1 as well as with Rad51 but did not observe the presence of 53BP1 at γH2AX foci in IVF zygotes. Our finding shows the presence of DSBs in IVF zygotes and suggests the capability of homologous recombination repair. The lack of 53BP1, a component of homologous recombination repair, which usually co-localizes with γH2AX foci at exogenously induced DSBs (Schultz et al. 2000 J. Cell. Biol. 151, 1381–1390) poses the possibility that the mechanism present in early embryos differs substantially from that involved in DNA repair of DSBs in somatic cells.

scholarly journals Databases and Bioinformatics Tools for the Study of DNA Repair

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Kaja Milanowska ◽  
Kristian Rother ◽  
Janusz M. Bujnicki
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Excision Repair ◽  
Uv Light ◽  
Dna Lesions ◽  
Environmental Chemicals ◽  
Nonhomologous End Joining ◽  
End Joining ◽  
Repair Mechanisms ◽  
Base Excision

DNA is continuously exposed to many different damaging agents such as environmental chemicals, UV light, ionizing radiation, and reactive cellular metabolites. DNA lesions can result in different phenotypical consequences ranging from a number of diseases, including cancer, to cellular malfunction, cell death, or aging. To counteract the deleterious effects of DNA damage, cells have developed various repair systems, including biochemical pathways responsible for the removal of single-strand lesions such as base excision repair (BER) and nucleotide excision repair (NER) or specialized polymerases temporarily taking over lesion-arrested DNA polymerases during the S phase in translesion synthesis (TLS). There are also other mechanisms of DNA repair such as homologous recombination repair (HRR), nonhomologous end-joining repair (NHEJ), or DNA damage response system (DDR). This paper reviews bioinformatics resources specialized in disseminating information about DNA repair pathways, proteins involved in repair mechanisms, damaging agents, and DNA lesions.

Response of Base Excision Repair Enzymes to Complex DNA Lesions

2001 ◽  
Vol 156 (5) ◽  
pp. 584-589 ◽  
Author(s):  
M. Weinfeld ◽  
A. Rasouli-Nia ◽  
M. A. Chaudhry ◽  
R. A. Britten
Keyword(s):  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Repair Enzymes ◽  
Base Excision

Role of nucleotide- and base-excision repair in genotoxin-induced neuronal cell death

DNA Repair ◽  
2004 ◽  
Vol 3 (6) ◽  
pp. 617-627 ◽  
Author(s):  
G.E Kisby ◽  
H Lesselroth ◽  
A Olivas ◽  
L Samson ◽  
B Gold ◽  
...  
Keyword(s):  
Cell Death ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Base Excision

scholarly journals Role of Base Excision Repair Pathway in the Processing of Complex DNA Damage Generated by Oxidative Stress and Anticancer Drugs

2021 ◽  
Vol 8 ◽  
Author(s):  
Yeldar Baiken ◽  
Damira Kanayeva ◽  
Sabira Taipakova ◽  
Regina Groisman ◽  
Alexander A. Ishchenko ◽  
...  
Keyword(s):  
Dna Damage ◽  
Base Excision Repair ◽  
Genome Instability ◽  
Excision Repair ◽  
Chromosomal Rearrangements ◽  
Strand Break ◽  
Dna Lesions ◽  
Complex Nature ◽  
Base Excision

Chemical alterations in DNA induced by genotoxic factors can have a complex nature such as bulky DNA adducts, interstrand DNA cross-links (ICLs), and clustered DNA lesions (including double-strand breaks, DSB). Complex DNA damage (CDD) has a complex character/structure as compared to singular lesions like randomly distributed abasic sites, deaminated, alkylated, and oxidized DNA bases. CDD is thought to be critical since they are more challenging to repair than singular lesions. Although CDD naturally constitutes a relatively minor fraction of the overall DNA damage induced by free radicals, DNA cross-linking agents, and ionizing radiation, if left unrepaired, these lesions cause a number of serious consequences, such as gross chromosomal rearrangements and genome instability. If not tightly controlled, the repair of ICLs and clustered bi-stranded oxidized bases via DNA excision repair will either inhibit initial steps of repair or produce persistent chromosomal breaks and consequently be lethal for the cells. Biochemical and genetic evidences indicate that the removal of CDD requires concurrent involvement of a number of distinct DNA repair pathways including poly(ADP-ribose) polymerase (PARP)-mediated DNA strand break repair, base excision repair (BER), nucleotide incision repair (NIR), global genome and transcription coupled nucleotide excision repair (GG-NER and TC-NER, respectively), mismatch repair (MMR), homologous recombination (HR), non-homologous end joining (NHEJ), and translesion DNA synthesis (TLS) pathways. In this review, we describe the role of DNA glycosylase-mediated BER pathway in the removal of complex DNA lesions.

scholarly journals When UDG and hAPE1 Meet Cyclopurines. How (5′R) and (5′S) 5′,8-Cyclo-2′-deoxyadenosine and 5′,8-Cyclo-2′-deoxyguanosine Affect UDG and hAPE1 Activity?

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5177
Author(s):  
Michał Szewczuk ◽  
Karolina Boguszewska ◽  
Julia Kaźmierczak-Barańska ◽  
Bolesław T. Karwowski
Keyword(s):  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Repair System ◽  
Cellular Mechanisms ◽  
Uracil Dna Glycosylase ◽  
Base Excision ◽  
Base Excision Repair System ◽  
Synthetic Oligonucleotides ◽  
Ap Site

Ionizing radiation is a factor that seriously damages cellular mechanisms/macromolecules, e.g., by inducing damage in the human genome, such as 5′,8-cyclo-2′-deoxypurines (cdPus). CdPus may become a component of clustered DNA lesions (CDL), which are notably unfavorable for the base excision repair system (BER). In this study, the influence of 5′S and 5′R diastereomers of 5′,8-cyclo-2′-deoxyadenosine (cdA) and 5′,8-cyclo-2′-deoxyguanosine (cdG) on the uracil-DNA glycosylase (UDG) and human AP site endonuclease 1 (hAPE1) activity has been taken under consideration. Synthetic oligonucleotides containing 2′-deoxyuridine (dU) and cdPu were used as a model of single-stranded CDL. The activity of the UDG and hAPE1 enzymes decreased in the presence of RcdG compared to ScdG. Contrary to the above, ScdA reduced enzyme activity more than RcdA. The presented results show the influence of cdPus lesions located within CDL on the activity of the initial stages of BER dependently on their position toward dU. Numerous studies have shown the biological importance of cdPus (e.g., as a risk of carcinogenesis). Due to that, it is important to understand how to recognize and eliminate this type of DNA damage from the genome.

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