title: Base excision repair modulation as a risk factor for human cancers.
abstract: Oxidative DNA damage and DNA repair mediate the development of several human pathologies, including cancer. The major pathway for oxidative DNA damage repair is base excision repair (BER). Functional assays performed in blood leukocytes of cancer patients and matched controls show that specific BER pathways are decreased in cancer patients, and may be risk factors. These include 8-oxoguanine (8-oxoG) repair in lung and head and neck cancer patients and repair of lipid peroxidation (LPO) induced 1,N(6)-ethenoadenine (epsilonA) in lung cancer patients. Decrease of excision of LPO-induced DNA damage, epsilonA and 3,N(4)-ethenocytosine (epsilonC) was observed in blood leukocytes of patients developing lung adenocarcinoma, specific histological type of cancer related to inflammation and healing of scars. BER proteins activity depends on gene polymorphism, interactions between BER system partners and post-translational modifications. Polymorphisms of DNA glycosylases may change their enzymatic activities, and some polymorphisms increase the risk of inflammation-related cancers, colorectal, lung and other types. Polymorphisms of BER platform protein, XRCC1 are connected with increased risk of tobacco-related cancers. BER efficiency may also be changed by reactive oxygen species and some diet components, which induce transcription of several glycosylases as well as a major human AP-endonuclease, APE1. BER is also changed in tumors in comparison to unaffected surrounding tissues, and this change may be due to transcription stimulation, post-translational modification of BER enzymes as well as protein-protein interactions. Modulation of BER enzymes activities may be, then, an important factor determining the risk of cancer and also may participate in cancer development.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland. tudek@ibb.waw.pl
authors.forename: Barbara
authors.initials: B
authors.lastname: Tudek
mesh_terms: D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004249:DNA Damage; D045647:DNA Glycosylases / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D015394:Molecular Structure; D009369:Neoplasms / Q000235:genetics*; D018384:Oxidative Stress; D011110:Polymorphism, Genetic; D011499:Protein Processing, Post-Translational; D012307:Risk Factors; D014158:Transcription, Genetic; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; D004247:DNA; D045647:DNA Glycosylases