F our-month-old C57BL/6 mice expressing a truncated protein of the DNA repair gene Xrcc1 (1) were treated with the aklyating carcinogen azoxymethane (AOM). Six months later, when tested, more than 90% of XRCC1 mutant mice treated with AOM had abnormal-appearing livers (Fig. 1b), whereas more than 80% of wild-type littermates had normal-appearing livers (Fig. 1a). The livers of the mutant mice h...

Hamster EM9 cells, which lack Xrcc1 protein, have reduced levels of DNA ligase III and are defective in nuclear base excision repair. The Xrcc1 protein stabilizes DNA ligase III and may even play a direct role in catalyzing base excision repair. Since DNA ligase III is also thought to function in mitochondrial base excision repair, it seemed likely that mitochondrial DNA ligase III function wou...

Hereditary genetic defects in DNA repair lead to increased risk of cancer. Polymorphisms in several DNA repair genes have been identified; however, the impact on repair phenotype has not been elucidated. We explored the relationship between polymorphisms in the DNA repair enzyme, XRCC1 (codons 194, 280, and 399), and genotoxic end points measured in two populations: (a) placental aflatoxin B1 D...

Aprataxin and PNKP-like factor (APLF) is a DNA repair factor containing a forkhead-associated (FHA) domain that supports binding to the phosphorylated FHA domain binding motifs (FBMs) in XRCC1 and XRCC4. We have characterized the interaction of the APLF FHA domain with phosphorylated XRCC1 peptides using crystallographic, NMR, and fluorescence polarization studies. The FHA-FBM interactions exhi...

Laryngeal cancer is the major malignant tumor affecting the upper respiratory tract. Previous studies have reported on the association between XRCC1 genetic polymorphisms and risk of laryngeal cancer, but with conflicting results. In this study, we attempted to assess the association between XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphisms and risk of laryngeal cancer in a Chinese populat...