Search results for "rase"
showing 10 items of 4343 documents
Poly(ADP-ribosyl)ation accelerates DNA repair in a pathway dependent on Cockayne syndrome B protein
2003
Activation of poly(ADP-ribose)polymerases 1 and 2 (PARP-1 and PARP-2) is one of the earliest responses of mammalian cells to DNA damage by numerous genotoxic agents. We have analysed the influence of PARP inhibition, either achieved by over-expression of the DNA binding domain of PARP-1 or by treatment with 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinolinone, on the repair of single-strand breaks (SSB), pyrimidine dimers and oxidative base modifications sensitive to Fpg protein (mostly 8-hydroxyguanine) in mammalian cells at very low, non-cytotoxic levels of DNA damage. The data show that the repair rates of all three types of DNA damage are significantly lower in PARP-inhibited c…
Parvovirus B19 nonstructural protein-induced damage of cellular DNA and resultant apoptosis.
2010
Parvovirus B19 is a widespread virus with diverse clinical presentations. The viral nonstructural protein, NS1, binds to and cleaves the viral genome, and induces apoptosis when transfected into nonpermissive cells, such as hepatocytes. We hypothesized that the cytotoxicity of NS1 in such cells results from chromosomal DNA damage caused by the DNA-nicking and DNA-attaching activities of NS1. Upon testing this hypothesis, we found that NS1 covalently binds to cellular DNA and is modified by PARP, an enzyme involved in repairing single-stranded DNA nicks. We furthermore discovered that the DNA nick repair pathway initiated by poly(ADPribose)polymerase and the DNA repair pathways initiated by …
Role of glutathione in cell nucleus
2010
Cells with high proliferation rate have high glutathione levels. This typical feature of cancer cells is viewed usually as a defence mechanism against ionizing radiation or chemotherapy. Efforts have been made in order to decrease cellular glutathione levels in tumours as a necessary pre-treatment for cancer therapy. However, very few reports have considered cellular glutathione as a physiological tool for cells to proliferate and that most of this high glutathione levels were located in the nucleus. The role of nuclear glutathione in cell physiology has become more important in the last years. This review summarizes new findings that point to the nuclear reduced status as an environment th…
DNA Junction Ligands Trigger DNA Damage and Are Synthetic Lethal with DNA Repair Inhibitors in Cancer Cells.
2019
International audience; Translocation of DNA and RNA polymerases along their duplex substrates results in DNA supercoiling. This torsional stress promotes the formation of plectonemic structures, including three-way DNA junction (TWJ), which can block DNA transactions and lead to DNA damage. While cells have evolved multiple mechanisms to prevent the accumulation of such structures, stabilizing TWJ through ad hoc ligands offer an opportunity to trigger DNA damage in cells with high level of transcription and replication, such as cancer cells. Here, we develop a series of azacryptand-based TWJ ligands, we thoroughly characterize their TWJ-interacting properties in vitro and demonstrate their…
Lentiviral-Mediated Gene Therapy in Fanconi Anemia-A Mice Reveals Long-Term Engraftment and Continuous Turnover of Corrected HSCs
2015
International audience; Fanconi anemia is a DNA repair-deficiency syndrome mainly characterized by cancer predisposition and bone marrow failure. Trying to restore the hematopoietic function in these patients, lentiviral vector-mediated gene therapy trials have recently been proposed. However, because no insertional oncogenesis studies have been conducted so far in DNA repair-deficiency syndromes such as Fanconi anemia, we have carried out a genome-wide screening of lentiviral insertion sites after the gene correction of Fanca-/- hematopoietic stem cells (HSCs), using LAM-PCR and 454-pyrosequencing. Our studies first demonstrated that transduction of Fanca-/- HSCs with a lentiviral vector d…
EGFP Reporters for Direct and Sensitive Detection of Mutagenic Bypass of DNA Lesions
2020
The sustainment of replication and transcription of damaged DNA is essential for cell survival under genotoxic stress
Thoughts on What Chemists Can Contribute to Fighting SARS-CoV-2 - A Short Note on Hand Sanitizers, Drug Candidates and Outreach.
2020
Abstract The SARS‐CoV‐2 outbreak causing the respiratory disease COVID‐19 has left many chemists in academia without an obvious option to contribute to fighting the pandemic. Some of our recent experiences indicate that there are ways to overcome this dilemma. A three‐pronged approach is proposed.
Mechanisms and consequences of methylating agent-induced SCEs and chromosomal aberrations: a long road traveled and still a far way to go.
2003
Since the milestone work of Evans and Scott, demonstrating the replication dependence of alkylation-induced aberrations, and Obe and Natarajan, pointing to the critical role of DNA double-strand breaks (DSBs) as the ultimate trigger of aberrations, the field has grown extensively. A notable example is the identification of DNA methylation lesions provoking chromosome breakage (clastogenic) effects, which made it possible to model clastogenic pathways evoked by genotoxins. Experiments with repair-deficient mutants and transgenic cell lines revealed both O<sup>6</sup>-methylguanine (O<sup>6</sup>MeG) and N- methylpurines as critical lesions. For S<sub>N</sub&g…
Late activation of stress kinases (SAPK/JNK) by genotoxins requires the DNA repair proteins DNA-PKcs and CSB.
2005
Although genotoxic agents are powerful inducers of stress kinases (SAPK/JNK), the contribution of DNA damage itself to this response is unknown. Therefore, SAPK/JNK activation of cells harboring specific defects in DNA damage-recognition mechanisms was studied. Dual phosphorylation of SAPK/JNK by the genotoxin methyl methanesulfonate (MMS) occurred in two waves. The early response (≤2 h after exposure) was similar in cells knockout for ATM, PARP, p53, and CSB or defective in DNA-PKcscompared with wild-type cells. The late response however (≥4 h), was drastically reduced in DNA-PKcsand Cockayne's syndrome B (CSB)-deficient cells. Similar results were obtained with human cells lacking DNA-PKc…
Histone carbonylation occurs in proliferating cells
2012
12 páginas, 10 figuras (que no es encuentran en este documento, se pueden ver en: http://www.sciencedirect.com/science/article/pii/S0891584912000664)