scholarly journals Genome Instability and DNA Repair in Cancer

2021 ◽  
Author(s):  
Bhaswatee Das ◽  
Bipasha Choudhury ◽  
Aditya Kumar ◽  
Vishwa Jyoti Baruah
Keyword(s):  
Dna Repair ◽  
Genome Instability ◽  
Repair Process ◽  
Repair System ◽  
Dna Repair Genes ◽  
Genomic Locus ◽  
Dna Repair Mechanisms ◽  
Repair Mechanisms ◽  
Or Genes ◽  
Repair Genes

Mutations in genome are essential for evolution but if the frequency of mutation increases it can evince to be detrimental, for a steady maintenance there exist a detailed complex system of surveillance and repair of DNA defects. Therefore, fault in DNA repair processes raises the probability of genomic instability and cancer in organisms. Genome instability encompasses various aspects of mutations from indels to various somatic variants. The chapter tries to present an overview of how cancer puts up several ways to ensure suppression of the fidelity in our DNA repair system. Cancer cells assure failure of efficient DNA repair mechanisms by innumerous ways, by mutation and epigenetic modifications in repair genes themselves or genes controlling their expression and functions, other by some catastrophic events like kataegis, chromothripsis and chromoplexy. These are clustered mutations taking place at a particular genomic locus which deluge the repair process. Cancer generation and evolution is dependent largely on genome instability, so it applies many strategies to overcome one of its basic obstacles that is DNA repair, targeting these DNA repair genes has also demonstrated to be helpful in cancer therapy; but an intricate understanding of recalcitrant process and mechanisms of drug resistant in cancer will further enhance the potential in them.

scholarly journals Expression of DNA repair and metabolic genes in response to a flavonoid-rich diet

2007 ◽  
Vol 98 (3) ◽  
pp. 525-533 ◽  
Author(s):  
Simonetta Guarrera ◽  
Carlotta Sacerdote ◽  
Laura Fiorini ◽  
Rosa Marsala ◽  
Silvia Polidoro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Repair ◽  
Significant Negative Correlation ◽  
Dna Repair Genes ◽  
Metabolic Genes ◽  
Damage Repair ◽  
Flavonoid Intake ◽  
Repair Mechanisms ◽  
Repair Genes

A diet rich in fruit and vegetables can be effective in the reduction of oxidative stress, through the antioxidant effects of phytochemicals and other mechanisms. Protection against the carcinogenic effects of chemicals may also be exerted by an enhancement of detoxification and DNA damage repair mechanisms. To investigate a putative effect of flavonoids, a class of polyphenols, on the regulation of the gene expression of DNA repair and metabolic genes, a 1-month flavonoid-rich diet was administered to thirty healthy male smokers, nine of whom underwent gene expression analysis. We postulated that tobacco smoke is a powerful source of reactive oxygen species. The expression level of twelve genes (APEX, ERCC1, ERCC2, ERCC4, MGMT, OGG1, XPA, XPC, XRCC1, XRCC3, AHR, CYP1A1) was investigated. We found a significant increase (P < 0·001) in flavonoid intake. Urinary phenolic content and anti-mutagenicity did not significantly change after diet, nor was a correlation found between flavonoid intake and urinary phenolic levels or anti-mutagenicity. Phenolic levels showed a significant positive correlation with urinary anti-mutagenicity. AHR levels were significantly reduced after the diet (P = 0·038), whereas the other genes showed a generalized up regulation, significant for XRCC3 gene (P = 0·038). Also in the context of a generalized up regulation of DNA repair genes, we found a non-significant negative correlation between flavonoid intake and the expression of all the DNA repair genes. Larger studies are needed to clarify the possible effects of flavonoids in vivo; our preliminary results could help to better plan new studies on gene expression and diet.

scholarly journals Homologous Recombination Repair Polymorphisms and the Risk for Osteosarcoma / Polimorfizam Gena Odgovornih Za Reparaciju Dnk Homolognom Rekombinacijom I Rizikza Pojavu Osteosarkoma

2015 ◽  
Vol 34 (2) ◽  
pp. 200-206 ◽  
Author(s):  
Katja Goričar ◽  
Viljem Kovač ◽  
Janez Jazbec ◽  
Janez Lamovec ◽  
Vita Dolžan
Keyword(s):  
Dna Repair ◽  
Homologous Recombination ◽  
Genome Stability ◽  
Cancer Susceptibility ◽  
Homologous Recombination Repair ◽  
Nucleotide Polymorphisms ◽  
Dna Repair Mechanisms ◽  
Recombination Repair ◽  
Repair Mechanisms ◽  
Repair Genes

Summary Background: DNA repair mechanisms are essential for maintaining genome stability, and genetic variability in DNA repair genes may contribute to cancer susceptibility. Our aim was to evaluate the influence of polymorphisms in the homologous recombination repair genes XRCC3, RAD51, and NBN on the risk for osteosarcoma. Methods: In total, 79 osteosarcoma cases and 373 controls were genotyped for eight single nucleotide polymorphisms (SNPs) in XRCC3, RAD51, and NBN. Logistic regression was used to determine the association of these SNPs with risk for osteosarcoma. Results: None of the investigated SNPs was associated with risk for osteosarcoma in the whole cohort of patients, however, in patients diagnosed before the age of thirty years XRCC3 rs861539 C>T and NBN rs1805794 G>C were associated with significantly decreased risk for osteosarcoma (P=0.047, OR=0.54, 95% CI=0.30-0.99 and P=0.036, OR=0.42, 95% CI=0.19-0.94, respectively). Moreover, in the carriers of a combination of polymorphic alleles in both SNPs risk for osteosarcoma was decreased even more significantly (Ptrend=0.007). The risk for developing osteosarcoma was the lowest in patients with no wild-type alleles for both SNPs (P=0.039, OR=0.31, 95% CI=0.10-0.94). Conclusions: Our results suggest that polymorphisms in homologous recombination repair genes might contribute to risk for osteosarcoma in patients diagnosed below the age of thirty years.

scholarly journals Lasting DNA Damage and Aberrant DNA Repair Gene Expression Profile Are Associated with Post-Chronic Cadmium Exposure in Human Bronchial Epithelial Cells

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 842 ◽  
Author(s):  
Heng Wee Tan ◽  
Zhan-Ling Liang ◽  
Yue Yao ◽  
Dan-Dan Wu ◽  
Hai-Ying Mo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Dna Repair ◽  
Human Lung ◽  
Repair System ◽  
Dna Repair Genes ◽  
Repair Gene ◽  
Dna Repair Gene ◽  
Repair Genes ◽  
Cd Exposure

Cadmium (Cd) is a widespread environmental pollutant and carcinogen. Although the exact mechanisms of Cd-induced carcinogenesis remain unclear, previous acute/chronic Cd exposure studies have shown that Cd exerts its cytotoxic and carcinogenic effects through multiple mechanisms, including interference with the DNA repair system. However, the effects of post-chronic Cd exposure remain unknown. Here, we establish a unique post-chronic Cd-exposed human lung cell model (the “CR0” cells) and investigate the effects of post-chronic Cd exposure on the DNA repair system. We found that the CR0 cells retained Cd-resistant property even though it was grown in Cd-free culture medium for over a year. The CR0 cells had lasting DNA damage due to reduced DNA repair capacity and an aberrant DNA repair gene expression profile. A total of 12 DNA repair genes associated with post-chronic Cd exposure were identified, and they could be potential biomarkers for identifying post-chronic Cd exposure. Clinical database analysis suggests that some of the DNA repair genes play a role in lung cancer patients with different smoking histories. Generally, CR0 cells were more sensitive to chemotherapeutic (cisplatin, gemcitabine, and vinorelbine tartrate) and DNA damaging (H2O2) agents, which may represent a double-edged sword for cancer prevention and treatment. Overall, we demonstrated for the first time that the effects of post-chronic Cd exposure on human lung cells are long-lasting and different from that of acute and chronic exposures. Findings from our study unveiled a new perspective on Cd-induced carcinogenesis—the post-chronic exposure of Cd. This study encourages the field of post-exposure research which is crucial but has long been ignored.

scholarly journals Restoration of deficient DNA Repair Genes Mitigates Genome Instability and Increases Productivity of Chinese Hamster Ovary Cells

2021 ◽  
Author(s):  
Philipp N. Spahn ◽  
Xiaolin Zhang ◽  
Qing Hu ◽  
Nathaniel K. Hamaker ◽  
Hooman Hefzi ◽  
...  
Keyword(s):  
Dna Repair ◽  
Cell Line ◽  
Cell Lines ◽  
Chinese Hamster Ovary ◽  
Genome Instability ◽  
Therapeutic Proteins ◽  
Chinese Hamster ◽  
Dna Repair Genes ◽  
Cho Cell ◽  
Repair Genes

AbstractChinese Hamster Ovary (CHO) cells are the primary host used for manufacturing of therapeutic proteins. However, production instability of high-titer cell lines is a major problem and is associated with genome instability, as chromosomal aberrations reduce transgene copy number and decrease protein titer. We analyzed whole-genome sequencing data from 11 CHO cell lines and found deleterious single-nucleotide polymorphisms (SNPs) in DNA repair genes. Comparison with other mammalian cells confirmed DNA repair is compromised in CHO. Restoration of key DNA repair genes by SNP reversal or expression of intact cDNAs improved DNA repair and genome stability. Moreover, the restoration of LIG4 and XRCC6 in a CHO cell line expressing secreted alkaline phosphatase mitigated transgene copy loss and improved protein titer retention. These results show for the first time that correction of key DNA repair genes yields considerable improvements in stability and protein expression in CHO, and provide new opportunities for cell line development and a more efficient and sustainable production of therapeutic proteins.

scholarly journals Frequency of Variants in DNA-Repair Genes in a Southwest Colombian Population

2019 ◽  
Vol 28 (03) ◽  
pp. 226-233
Author(s):  
Herney Andrés García-Perdomo ◽  
Mailyn Alejandra Bedoya Saldarriaga ◽  
Adalberto Sánchez
Keyword(s):  
Dna Repair ◽  
San Diego ◽  
System Component ◽  
Repair System ◽  
Dna Repair Genes ◽  
Nucleotide Polymorphisms ◽  
Mismatch Repair System ◽  
Thermo Fisher Scientific ◽  
Brca1 Brca2 ◽  
Repair Genes

Abstract Objective To describe the frequency of mutations in DNA-repair genes in a southwestern Colombian population. Methods We have designed an observational study, including 162 people from all ages from southwest Colombia. We have extracted and collected their DNA in filters. We have immersed the DNA in a phosphate buffer along with DNeasy package (Thermo Fisher Scientific, Waltham, MA, USA). The preparation process was with the TruSeq Exome Library Prep (Illumina, Inc. San Diego, CA, USA), then the obtained libraries were normalized with TruSeq Rapid Exome (Illumina, Inc. San Diego, CA, USA). We sequenced the full exome and identified the variants associated with 12 genes (ataxia telangiectasia mutated [ATM], BRCA1 DNA repair associated [BRCA1], BRCA2 DNA repair associated [BRCA2], checkpoint kinase 2 [CHEK2], epithelial cell adhesion molecule [EPCAM], homeobox protein Hox-B13 [HOXB13], mutS homolog 1, 2 and 6 [MLH1, MSH2, MSH6], nibrin [NBN], PMS1 homolog 2, mismatch repair system component [PMS2], and tumor protein p53 [TP53]). Descriptive statistics were performed with the R software (The R Foundation for Statistical Computing, Vienna, Austria). Results A total of 7,315,466 pieces of data were sequenced in this population. The most frequently mutated genes were ATM (1,221 pieces of data; 13.2%), BRCA1 (1,178 pieces of data; 12.8%), BRCA2 (1,484 pieces of data; 16.12%), and NBN (965 pieces of data; 10.42%). The most common single nucleotide polymorphisms (SNPs) in these 12 genes were the following: BRCA2 (rs169547, rs206075, rs206076); ATM (rs659243, rs228589); TP53 (rs1625895, rs1042522, rs1642785); PMS2 (rs2228006, rs1805319); NBN (rs709816); and MSH6 (rs3136367) Conclusion The BRCA2, ATM, BRCA1 and NBN DNA-repair genes were the most frequently mutated in this southwestern Colombian Population.

scholarly journals Incorporation of a nucleoside analog maps genome repair sites in post-mitotic human neurons

2020 ◽  
Author(s):  
Dylan A. Reid ◽  
Patrick J. Reed ◽  
Johannes C.M. Schlachetzki ◽  
Grace Chou ◽  
Sahaana Chandran ◽  
...  
Keyword(s):  
Dna Repair ◽  
Genome Instability ◽  
Human Life ◽  
Terminal Differentiation ◽  
Genome Integrity ◽  
Dna Repair Mechanisms ◽  
Human Neurons ◽  
Repair Mechanisms ◽  
And Function ◽  
Human Life Span

AbstractNeurons are the longest-living cells in our bodies, becoming post-mitotic in early development upon terminal differentiation. Their lack of DNA replication makes them reliant on DNA repair mechanisms to maintain genome fidelity. These repair mechanisms decline with age, potentially giving rise to genomic dysfunction that may influence cognitive decline and neurodegenerative diseases. Despite this challenge, our knowledge of how genome instability emerges and what mechanisms neurons and other long-lived cells may have evolved to protect their genome integrity over the human life span is limited. Using a targeted sequencing approach, we demonstrate that neurons consolidate much of their DNA repair efforts into well-defined hotspots that protect genes that are essential for their identity and function. Our findings provide a basis to understand genome integrity as it relates to aging and disease in the nervous system.One Sentence SummaryRecurrent DNA repair hotspots in neurons are linked to genes essential for identity and function.

Association between polymorphisms of DNA repair genes and risk of type 2 diabetes mellitus in the Turkish population

2017 ◽  
Vol 43 (2) ◽  
pp. 167-172
Author(s):  
Neslihan Tokmak ◽  
Umit Yilmaz ◽  
Nesibe Yilmaz ◽  
Leman Melis Yurdum ◽  
Nihal Yigitbasi ◽  
...  
Keyword(s):  
Dna Repair ◽  
Hdl Cholesterol ◽  
Turkish Population ◽  
Study Groups ◽  
Control Group ◽  
Dna Repair Genes ◽  
Cholesterol Levels ◽  
Repair Mechanisms ◽  
And Control ◽  
Repair Genes

Abstract Objectives: DNA repair mechanisms work insufficiently in T2DM patients and hyperglycemia seen in diabetes disturbs the oxidant-antioxidant balance thus cause oxidative damage on DNA. The effects of the DNA repair genes’ have not yet been investigated on diabetes. The aim of this study was to investigate the association between APE1 Asp148Glu and XPG Asp1104His polymorphisms with T2DM in the Turkish population. Material and methods: Sixty-five T2DM patients and 54 healthy individuals were included to this study as control. The polymerase chain reaction-restriction fragment length polymorphism techniques were used. Results: When the study groups were compared, serum HDL-cholesterol levels were found statistically elevated in the controls. Once the APE1 Asp148Glu polymorphism distribution between the patient and control groups was investigated, the Glu/Glu genotype ratio was found significantly higher in the control group. Furthermore, the Asp/Glu genotype and the Asp allele prevalences were observed to be higher in the patient group. Also, patients with the Asp/Asp genotype had higher serum HDL-cholesterol levels than the others. Conclusion: Despite the small number of subjects included, it could be interpreted that the Glu allele of the APE1 Asp148Glu polymorphism might be protective against and the Asp allele may be contributing to the development of diabetes.

scholarly journals Restoration of deficient DNA Repair Genes Mitigates Genome Instability and Increases Productivity of Chinese Hamster Ovary Cells

2021 ◽  
Author(s):  
Philipp Spahn ◽  
Xiaolin Zhang ◽  
Qing Hu ◽  
Nathaniel Hamaker ◽  
Hooman Hefzi ◽  
...  
Keyword(s):  
Dna Repair ◽  
Cell Line ◽  
Cell Lines ◽  
Chinese Hamster Ovary ◽  
Genome Instability ◽  
Therapeutic Proteins ◽  
Chinese Hamster ◽  
Dna Repair Genes ◽  
Cho Cell ◽  
Repair Genes

Abstract Chinese Hamster Ovary (CHO) cells are the primary host used for manufacturing of therapeutic proteins. However, production instability of high-titer cell lines is a major problem and is associated with genome instability, as chromosomal aberrations reduce transgene copy number and decrease protein titer. We analyzed whole-genome sequencing data from 11 CHO cell lines and found deleterious single-nucleotide polymorphisms (SNPs) in DNA repair genes. Comparison with other mammalian cells confirmed DNA repair is compromised in CHO. Restoration of key DNA repair genes by SNP reversal or expression of intact cDNAs improved DNA repair and genome stability. Moreover, the restoration of LIG4 and XRCC6 in a CHO cell line expressing secreted alkaline phosphatase mitigated transgene copy loss and improved protein titer retention. These results show for the first time that correction of key DNA repair genes yields considerable improvements in stability and protein expression in CHO, and provide new opportunities for cell line development and a more efficient and sustainable production of therapeutic proteins.

Truncating variants in DNA-repair genes and their effect on AAO of hereditary breast cancer

2018 ◽  
Author(s):  
I Sepahi ◽  
U Faust ◽  
M Sturm ◽  
K Bosse ◽  
M Kehrer ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Repair ◽  
Hereditary Breast Cancer ◽  
Dna Repair Genes ◽  
Repair Genes
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