Nucleotide fluctuation of RecA repair gene in Siberian permafrost Psychrobacter cryohalolentis K5

Background: The therapeutically important DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) is silenced by promoter methylation in human brain cancers. The co-players/regulators associated with this process and the subsequent progression of MGMT gene transcription beyond the non-coding exon 1 are unknown. As a follow-up to our recent finding of a predicted second promoter mapped proximal to the exon 2 [Int. J. Mol. Sci.2021, 22(5), 2492], we addressed its significance in MGMT transcription. Methods: RT-PCR, RT q-PCR, and nuclear run-on transcription assays were performed to compare and contrast the transcription rates of exon 1 and exon 2 of the MGMT gene in glioblastoma cells. Results: Bioinformatic characterization of the predicted MGMT exon 2 promoter showed several consensus TATA box and INR motifs and the absence of CpG islands in contrast to the established TATA-less, CpG-rich, and GAF-bindable exon 1 promoter. RT-PCR showed very weak MGMT-E1 expression in MGMT-proficient SF188 and T98G GBM cells, compared to active transcription of MGMT-E2. In the MGMT-deficient SNB-19 cells, the expression of both exons remained weak. The RT q-PCR revealed that MGMT-E2 and MGMT-E5 expression was about 80- to 175-fold higher than that of E1 in SF188 and T98G cells. Nuclear run-on transcription assays using bromo-uridine immunocapture followed by RT q-PCR confirmed the exceptionally lower and higher transcription rates for MGMT-E1 and MGMT-E2, respectively. Conclusions: The results provide the first evidence for transcriptional pausing at the promoter 1- and non-coding exon 1 junction of the human MGMT gene and its activation/elongation through the protein-coding exons 2 through 5, possibly mediated by a second promoter. The findings offer novel insight into the regulation of MGMT transcription in glioma and other cancer types.

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A DNA damage repair gene‐associated signature predicts responses of patients with advanced soft‐tissue sarcoma to treatment with trabectedin

Molecular Oncology ◽

10.1002/1878-0261.12996 ◽

2021 ◽

Author(s):

David S. Moura ◽

Maria Peña‐Chilet ◽

Juan Antonio Cordero Varela ◽

Ramiro Alvarez‐Alegret ◽

Carolina Agra‐Pujol ◽

...

Keyword(s):

Dna Damage ◽

Soft Tissue ◽

Soft Tissue Sarcoma ◽

Dna Damage Repair ◽

Advanced Soft Tissue Sarcoma ◽

Repair Gene ◽

Damage Repair

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Non-Ionizing Millimeter Waves Non-Thermal Radiation of Saccharomyces cerevisiae—Insights and Interactions

Applied Sciences ◽

10.3390/app11146635 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6635

Author(s):

Ayan Barbora ◽

Shailendra Rajput ◽

Konstantin Komoshvili ◽

Jacob Levitan ◽

Asher Yahalom ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Division ◽

Millimeter Waves ◽

Model Organism ◽

Horn Antenna ◽

Colony Growth ◽

Genetic Alterations ◽

Power Delivery ◽

Repair Gene ◽

Safety Standards

Non-ionizing millimeter-waves (MMW) interact with cells in a variety of ways. Here the inhibited cell division effect was investigated using 85–105 GHz MMW irradiation within the International Commission on Non-Ionizing Radiation Protection (ICNIRP) non-thermal 20 mW/cm2 safety standards. Irradiation using a power density of about 1.0 mW/cm2 SAR over 5–6 h on 50 cells/μL samples of Saccharomyces cerevisiae model organism resulted in 62% growth rate reduction compared to the control (sham). The effect was specific for 85–105 GHz range and was energy- and cell density-dependent. Irradiation of wild type and Δrad52 (DNA damage repair gene) deleted cells presented no differences of colony growth profiles indicating non-thermal MMW treatment does not cause permanent genetic alterations. Dose versus response relations studied using a standard horn antenna (~1.0 mW/cm2) and compared to that of a compact waveguide (17.17 mW/cm2) for increased power delivery resulted in complete termination of cell division via non-thermal processes supported by temperature rise measurements. We have shown that non-thermal MMW radiation has potential for future use in treatment of yeast related diseases and other targeted biomedical outcomes.

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DNA Repair Gene Polymorphism and the Risk of Mitral Chordae Tendineae Rupture

Disease Markers ◽

10.1155/2015/825020 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6

Author(s):

Aysel Kalayci Yigin ◽

Mehmet Bulent Vatan ◽

Ramazan Akdemir ◽

Muhammed Necati Murat Aksoy ◽

Mehmet Akif Cakar ◽

...

Keyword(s):

Dna Repair ◽

Fragment Length Polymorphism ◽

Control Group ◽

Chordae Tendineae ◽

Repair Gene ◽

Repair Capacity ◽

Dna Repair Capacity ◽

Dna Repair Gene ◽

Increased Risk ◽

Polymerase Chain

Polymorphisms in Lys939Gln XPC gene may diminish DNA repair capacity, eventually increasing the risk of carcinogenesis. The aim of the present study was to evaluate the significance of polymorphism Lys939Gln in XPC gene in patients with mitral chordae tendinea rupture (MCTR). Twenty-one patients with MCTR and thirty-seven age and sex matched controls were enrolled in the study. Genotyping of XPC gene Lys939Gln polymorphism was carried out using polymerase chain reaction- (PCR-) restriction fragment length polymorphism (RFLP). The frequencies of the heterozygote genotype (Lys/Gln-AC) and homozygote genotype (Gln/Gln-CC) were significantly different in MCTR as compared to control group, respectively (52.4% versus 43.2%,p=0.049; 38.15% versus 16.2%,p=0.018). Homozygote variant (Gln/Gln) genotype was significantly associated with increased risk of MCTR (OR = 2.059; 95% CI: 1.097–3.863;p=0.018). Heterozygote variant (Lys/Gln) genotype was also highly significantly associated with increased risk of MCTR (OR = 1.489; 95% CI: 1.041–2.129;p=0.049). The variant allele C was found to be significantly associated with MCTR (OR = 1.481; 95% CI: 1.101–1.992;p=0.011). This study has demonstrated the association of XPC gene Lys939Gln polymorphism with MCTR, which is significantly associated with increased risk of MCTR.

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DNA Repair Gene Polymorphisms and Susceptibility to Urothelial Carcinoma in a Southeastern European Population

Current Oncology ◽

10.3390/curroncol28030174 ◽

2021 ◽

Vol 28 (3) ◽

pp. 1879-1885

Author(s):

Maria Samara ◽

Maria Papathanassiou ◽

Lampros Mitrakas ◽

George Koukoulis ◽

Panagiotis J. Vlachostergios ◽

...

Keyword(s):

Dna Repair ◽

Urothelial Carcinoma ◽

European Population ◽

Nucleotide Polymorphisms ◽

Environmental Carcinogens ◽

Repair Gene ◽

High Exposure ◽

Dna Repair Gene ◽

Increased Risk ◽

Xrcc3 Thr241met

Single nucleotide polymorphisms (SNPs) in DNA repair genes may predispose to urothelial carcinoma of the bladder (UCB). This study focused on three specific SNPs in a population with high exposure to environmental carcinogens including tobacco and alcohol. A case-control study design was used to assess for presence of XPC PAT +/−, XRCC3 Thr241Met, and ERCC2 Lys751Gln DNA repair gene SNPs in peripheral blood from patients with UCB and healthy individuals. One hundred patients and equal number of healthy subjects were enrolled. The XPC PAT +/+ genotype was associated with a 2-fold increased risk of UCB (OR = 2.16; 95%CI: 1.14–4; p = 0.01). The −/+ and +/+ XPC PAT genotypes were more frequently present in patients with multiple versus single tumors (p = 0.01). No association was detected between ERCC2 Lys751Gln genotypes/alleles, and risk for developing UCB. Presence of the XRCC3 TT genotype (OR = 0.14; 95%CI:0.07–0.25; p < 0.01) and of the T allele overall (OR = 0.26; 95%CI:0.16–0.41; p < 0.01) conferred a protective effect against developing UCB. The XPC PAT −/+ and XRCC3 Thr241Met SNPs are associated with predisposition to UCB. The XPC PAT −/+ SNP is also an indicator of bladder tumor multiplicity, which might require a more individualized surveillance and treatment.

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Radio-adaptive response and correlation of non-homologous end joining repair gene polymorphisms [XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T)] in human peripheral blood mononuclear cells exposed to gamma radiation

Genes and Environment ◽

10.1186/s41021-021-00176-4 ◽

2021 ◽

Vol 43 (1) ◽

Author(s):

Shridevi Shelke ◽

Birajalaxmi Das

Keyword(s):

Dna Damage ◽

Mrna Expression ◽

Adaptive Response ◽

Gene Polymorphisms ◽

Significant Positive Correlation ◽

Human Pbmcs ◽

Mrna Expression Level ◽

Repair Gene ◽

Positive Correlation ◽

Nhej Repair

Abstract Background Radio-adaptive response (RAR) is transient phenomena, where cells conditioned with a small dose (priming) of ionizing radiation shows significantly reduced DNA damage with a subsequent high challenging dose. The role of DNA double strand break repair gene polymorphism in RAR is not known. In the present study attempt was made to find out the influence of NHEJ repair gene polymorphisms [a VNTR; XRCC5 (3R/2R/1R/0R); two single nucleotide polymorphisms (SNPs); XRCC6 (C/G) and XRCC7 (G/T)] with DNA damage, repair and mRNA expression in human PBMCs in dose and adaptive response studies. Genomic DNA extracted from venous blood samples of 20 random healthy donors (16 adaptive and 4 non-adaptive) and genotyping of NHEJ repair genes was carried out using PCR amplified length polymorphism. Results The dose response study revealed significant positive correlation of genotypes at XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T) with DNA damage. Donors having genotypes with 2R allele at XRCC5 showed significant positive correlation with mRNA expression level (0R/2R: r = 0.846, P = 0.034; 1R/2R: r = 0.698, P = 0.0001 and 2R/2R: r = 0.831, P = 0.0001) for dose response. Genotypes C/C and C/G of XRCC6 showed a significant positive correlation (P = 0.0001), whereas, genotype T/T of XRCC7 showed significant negative correlation (r = − 0.376, P = 0.041) with mRNA expression. Conclusion Interestingly, adaptive donors having C/G genotype of XRCC6 showed significantly higher (P < 0.05) mRNA expression level in primed cells suggesting their role in RAR. In addition, NHEJ repair gene polymorphisms play crucial role with radio-sensitivity and RAR in human PBMCs.

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Developmentally Regulated Oscillations in the Expression of UV Repair Genes in a Soilborne Plant Pathogen Dictate UV Repair Efficiency and Survival

mBio ◽

10.1128/mbio.02623-19 ◽

2019 ◽

Vol 10 (6) ◽

Author(s):

Shira Milo-Cochavi ◽

Sheera Adar ◽

Shay Covo

Keyword(s):

Gene Expression ◽

Fusarium Oxysporum ◽

Plant Pathogen ◽

Uv Light ◽

Sun Exposure ◽

The Sun ◽

Repair Gene ◽

Repair Capacity ◽

Content Type ◽

Repair Genes

ABSTRACT The ability to withstand UV damage shapes the ecology of microbes. While mechanisms of UV tolerance were extensively investigated in microorganisms regularly exposed to the sun, far less is known about UV repair of soilborne microorganisms. Fusarium oxysporum is a soilborne fungal plant pathogen that is resistant to UV light. We hypothesized that its UV repair capacity is induced to deal with irregular sun exposure. Unlike the SOS paradigm, our analysis revealed only sporadic increases and even decreases in UV repair gene expression following UVC irradiation or exposure to visible light. Strikingly, a major factor determining the expression of UV repair genes was the developmental status of the fungus. At the early stages of germination, the expression of photolyase increased while the expression of UV endonuclease decreased, and then the trend was reversed. These gene expression oscillations were dependent on cell cycle progression. Consequently, the contribution of photoreactivation to UV repair and survival was stronger at the beginning of germination than later when a filament was established. F. oxysporum germinates following cues from the host. Early on in germination, it is most vulnerable to UV; when the filament is established, the pathogen is protected from the sun because it is already within the host tissue. IMPORTANCE Fusarium oxysporum infects plants through the roots and therefore is not exposed to the sun regularly. However, the ability to survive sun exposure expands the distribution of the population. UV from the sun is toxic and mutagenic, and to survive sun exposure, fungi encode several DNA repair mechanisms. We found that Fusarium oxysporum has a gene expression program that activates photolyase at the first hours of germination when the pathogen is not established in the plant tissue. Later on, the expression of photolyase decreases, and the expression of a light-independent UV repair mechanism increases. We suggest a novel point of view to a very fundamental question of how soilborne microorganisms defend themselves against sudden UV exposure.

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