Accelerated repair and reduced mutagenicity of oxidative DNA damage in human bladder cells expressing the E. coli FPG protein.
Repair of some oxidized purines such as 8-oxo-7,8-dihydroguanine (8-oxoG) is inefficient in human cells in comparison to repair of other major endogenous lesions (e.g. uracil, abasic sites or oxidized pyrimidines). This is due to the poor catalytic properties of hOGG1, the major DNA glycosylase involved in 8-oxoG removal. The formamidopyrimidine DNA glycosylase (FPG) protein from E. coli is endowed with a potent 8-oxoG glycolytic activity coupled with a beta,delta-AP lyase. In this study, we have expressed FPG fused to the enhanced green fluorescent protein (EGFP) in human bladder cells to accelerate the repair of oxidative DNA damage. Cells expressing the fusion protein EGFP-FPG repaired 8-oxoG and AP sites at accelerated rates, in particular via the single-nucleotide insertion base excision repair (BER) pathway and were resistant to mutagenicity of the oxidizing carcinogen potassium bromate. FPG may stably protect human cells from some harmful effects of oxidative DNA damage.
Ropolo
Monica
M
Department of Translational Oncology, Experimental Oncology B Laboratory, Istituto Nazionale Ricerca Cancro, Largo Rosanna Benzi n. 10, 16132 Genova, Italy.
Geroldi
Alessandro
A
Degan
Paolo
P
Andreotti
Virginia
V
Zupo
Simona
S
Poggi
Alessandro
A
Reed
April
A
Kelley
Mark R
MR
Frosina
Guido
G
D001959:Bromates / Q000633:toxicity; D002273:Carcinogens / Q000633:toxicity; D018929:Cell Culture Techniques; D004249:DNA Damage; D004260:DNA Repair; D043382:DNA-Formamidopyrimidine Glycosylase / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005347:Fibroblasts; D049452:Green Fluorescent Proteins; D006147:Guanine / Q000031:analogs & derivatives / Q000633:toxicity; D006801:Humans; D018384:Oxidative Stress; D017382:Reactive Oxygen Species; D001743:Urinary Bladder / Q000166:cytology*; D001749:Urinary Bladder Neoplasms / Q000503:physiopathology
D001959:Bromates; D002273:Carcinogens; D029968:Escherichia coli Proteins; D017382:Reactive Oxygen Species; C019536:potassium bromate; D049452:Green Fluorescent Proteins; C024829:8-hydroxyguanine; D006147:Guanine; D043382:DNA-Formamidopyrimidine Glycosylase; C468610:DNA-formamidopyrimidine glycosylase, E coli