Many conventional chemotherapeutic drugs exert their cytotoxic function by inducing DNA damage in the tumor cell. Therefore, a cell-inherent DNA repair pathway, which reverses the DNA-damaging effect of the cytotoxic drugs, can mediate therapeutic resistance to chemotherapy. The monofunctional DNA-alkylating agent temozolomide (TMZ) is a commonly used chemotherapeutic drug and the gold standard...

Our cells are constantly exposed to insults from endogenous and exogenous agents that can introduce damage into our DNA and generate genomic instability. Many of these lesions cause structural damage to DNA and can alter or eliminate fundamental cellular processes, such as DNA replication or transcription. DNA lesions commonly include base and sugar modifications, singleand double-strand breaks...

To study the mechanism of DNA excision repair, a DNA repair system employing permeable mouse sarcoma (SR-C3H/He) cells was established and characterized. SR-C3H/He cells were permeabilized with a 0.0175% Triton X-100 solution. The permeable cells were treated with 1 mM ATP and 0.11 mM bleomycin, and then washed thoroughly to remove ATP and bleomycin. Repair DNA synthesis occurred in the bleomyc...

Akt phosphorylation has previously been described to be involved in mediating DNA damage repair through the nonhomologous end-joining (NHEJ) repair pathway. Yet the mechanism how Akt stimulates DNA-protein kinase catalytic subunit (DNA-PKcs)-dependent DNA double-strand break (DNA-DSB) repair has not been described so far. In the present study, we investigated the mechanism by which Akt can inte...

Malfunctioning of some dna repair pathways predisposes to certain types of cancer. impaired base excision repair, nucleotide excision repair, mismatch repair and recombination are implied in human tissues. these repair pathways are engaged very quickly in the cell when the external (chemical carcinogens) and internal (lipid peroxidation products) compounds react directly with dna. this reaction...

PURPOSE From numerous reports on proteins involved in DNA repair and telomere maintenance that physically associate with human telomerase reverse transcriptase (hTERT), we inferred that hTERT/telomerase might play a role in DNA repair. We investigated this possibility in normal human oral fibroblasts (NHOF) with and without ectopic expression of hTERT/telomerase. EXPERIMENTAL DESIGN To study ...

DNA repair is critical for maintaining genomic integrity. The DNA damage such as those induced by endogenous processes (methylation, hydroxylation, oxidation by free radicals) or by exogenous agents such as ionizing radiation, environmental toxins, and chemotherapy is processed through the DNA repair machinery in cells. At least six distinct DNA repair pathways have been described. A detailed d...

DNA repair mechanisms are critical for maintaining the integrity of genomic DNA, and their loss is associated with cancer predisposition syndromes. Studies in Saccharomyces cerevisiae have played a central role in elucidating the highly conserved mechanisms that promote eukaryotic genome stability. This review will focus on repair mechanisms that involve excision of a single strand from duplex ...

DNA repair is a system of defenses designed to protect the integrity of the genome. Deficiencies in this system likely lead to the development of cancer. The epidemiology of DNA repair capacity and of its effect on cancer susceptibility in humans is, therefore, an important area of investigation. We have summarized all of the published epidemiologic studies on DNA repair in human cancer through...

Nucleotide excision repair is a complex biochemical process that corrects DNA damage caused by a broad spectrum of physical and chemical agents. We examined the effect of the assembly of ultraviolet-irradiated plasmid DNA into nucleosomes on nucleotide excision repair supported by human cell extracts. Repair synthesis in unassembled UV-irradiated plasmid DNA was readily detected in extracts fro...