Cells from Cockayne syndrome patients are characterized by a deficiency in transcription-coupled repair (TCR) of UV-induced lesions. These cells have also been shown to be sensitive to oxidative stress and defective in TCR of some oxidative lesions. Because some discrepancies about this pathway have been recently reported in the literature, we describe here a system that allows us to analyze th...

8-Oxoguanine, a major oxidized base lesion formed by reactive oxygen species, causes G to T transversion mutations or leads to cell death in mammals if it accumulates in DNA. 8-Oxoguanine can originate as 8-oxo-dGTP, formed in the nucleotide pool, or by direct oxidation of the DNA guanine base. MTH1, also known as NUDT1, with 8-oxo-dGTP hydrolyzing activity, 8-oxoguanine DNA glycosylase (OGG1) ...

The common DNA base modification 8-oxo-7,8-dihydroguanine (8-oxo-G) affects the efficiency and fidelity of transcription. We constructed plasmid substrates carrying single 8-oxo-G residues, specifically positioned in the transcribed or the non-transcribed DNA strands, to investigate their effects on the expression of an EGFP reporter gene and to explore the role of base excision repair in the m...

Introduction Breast cancer is the most common cancer among western women. Except for inherited mutations in the BRCA1, BRCA2, ATM, and p53 genes, little is known about the genetic risk factors for breast cancer. Recently, polymorphisms in genes involved in repair of DNA double-strand breaks were associated with risk of breast cancer (1). It has been proposed that oxidative stress contributes to...

Oxidatively damaged bases in the genome are likely to be responsible for mutations leading to sporadic carcinogenesis. Two structurally similar DNA glycosylases, NTH1 and OGG1, which are able to excise most of these damaged bases, were identified previously in mammalian cells. A distinct family, consisting of two human DNA glycosylases orthologous to enzymes in Escherichia coli, has recently be...

OBJECTIVES The Ser326Cys polymorphism in the human 8-oxogunaine glycosylase (hOGG1) gene with lung cancer susceptibility had been investigated, but results were inconsistent and underpowered. The aim of this study was to conduct a meta-analysis assessing the association of hOGG1 Ser326Cys polymorphism with risk of lung cancer. MATERIALS AND METHODS Relevant studies were identified through a s...

Although the genotoxic mechanism(s) of hexavalent chromium (CrVI) carcinogenicity remain to be fully elucidated, intracellular reduction of CrVI and concomitant generation of reactive intermediates including reactive oxygen species and subsequent oxidative damage to DNA is believed to contribute to the process of carcinogenesis. In the current study, substantial interindividual variation (7.19-...

The Cut homeobox 1 (CUX1) gene is a target of loss-of-heterozygosity in many cancers, yet elevated CUX1 expression is frequently observed and is associated with shorter disease-free survival. The dual role of CUX1 in cancer is illustrated by the fact that most cell lines with CUX1 LOH display amplification of the remaining allele, suggesting that decreased CUX1 expression facilitates tumor deve...