Quantitation of DNA Adducts of Aristolochic Acids in Repair-Deficient Cells: A Mechanistic Study of the DNA Repair Mechanism
Chun-Kit Au, Chi‐Kong Chan, Ka-Ki Tung, Jiayin Zhang, Wan Chan
Abstract
Accumulating evidence has revealed that nephrotoxic and carcinogenic aristolochic acids (AAs) released from decaying Aristolochia clematitis L. weeds are soil and food grain contaminants in the Balkan Peninsula, while AA toxicity has been linked to induced DNA damage. In this study, we investigated the DNA repair mechanism that excises the aristolactam-DNA adducts in gene-knockout Escherichia coli cells. These results demonstrated that cell lines deficient in nucleotide excision repair (NER) machinery accumulated higher adduct levels, indicating that NER is the major mechanism responsible for the repair of these lesions. Furthermore, data also revealed the involvement of base excision repair enzymes in repairing the lesions but with lower contribution than NER.