Hijacking of the Human Alkyl-N-purine-DNA Glycosylase by 3,N4-Ethenocytosine, a Lipid Peroxidation-induced DNA Adduct

Lipid peroxidation generates aldehydes, which react with DNA bases, forming genotoxic exocyclic etheno(ϵ)-adducts. E-bases have been implicated in vinyl chloride-induced carcinogenesis, and increased levels of these DNA lesions formed by endogenous processes are found in human degenerative disorders. E-adducts are repaired by the base excision repair pathway. Here, we report the efficient biological hijacking of the human alkyl-N-purine-DNA glycosylase (ANPG) by 3,N4-ethenocytosine (ϵC) when present in DNA. Unlike the ethenopurines, ANPG does not excise, but binds to ϵC when present in either double-stranded or single-stranded DNA. We developed a direct assay, based on the fluorescence quenching mechanism of molecular beacons, to measure a DNA glycosylase activity. Molecular beacons containing modified residues have been used to demonstrate that the ϵC·ANPG interaction inhibits excision repair both in reconstituted systems and in cultured human cells. Furthermore, we show that the ϵC·ANPG complex blocks primer extension by the Klenow fragment of DNA polymerase I. These results suggest that ϵC could be more genotoxic than 1,N6-ethenoadenine (ϵA) residues in vivo. The proposed model of ANPG-mediated genotoxicity of ϵC provides a new insight in the molecular basis of lipid peroxidation-induced cell death and genome instability in cancer. Lipid peroxidation generates aldehydes, which react with DNA bases, forming genotoxic exocyclic etheno(ϵ)-adducts. E-bases have been implicated in vinyl chloride-induced carcinogenesis, and increased levels of these DNA lesions formed by endogenous processes are found in human degenerative disorders. E-adducts are repaired by the base excision repair pathway. Here, we report the efficient biological hijacking of the human alkyl-N-purine-DNA glycosylase (ANPG) by 3,N4-ethenocytosine (ϵC) when present in DNA. Unlike the ethenopurines, ANPG does not excise, but binds to ϵC when present in either double-stranded or single-stranded DNA. We developed a direct assay, based on the fluorescence quenching mechanism of molecular beacons, to measure a DNA glycosylase activity. Molecular beacons containing modified residues have been used to demonstrate that the ϵC·ANPG interaction inhibits excision repair both in reconstituted systems and in cultured human cells. Furthermore, we show that the ϵC·ANPG complex blocks primer extension by the Klenow fragment of DNA polymerase I. These results suggest that ϵC could be more genotoxic than 1,N6-ethenoadenine (ϵA) residues in vivo. The proposed model of ANPG-mediated genotoxicity of ϵC provides a new insight in the molecular basis of lipid peroxidation-induced cell death and genome instability in cancer. Oxidative stress generates reactive aldehydes, as a by-product of lipid peroxidation (LPO) 1The abbreviations used are: LPO, lipid peroxidation; ϵ, etheno; ϵA, 1,N6-ethenoadenine; ϵC, 3,N4-ethenocytosine; 1,N2-ϵG, 1,N2-ethenoguanine; Hx, hypoxanthine; I, inosine; THF, tetrahydrofuran; 8-oxoG, 7,8-dihydro-8-oxoguanine; DHU, 5,6-dihydrouracil; DHT, 5,6-dihydrothymine; 5ohU, 5-hydroxyuracil; AP, apurinic/apyrimidinic; BER, base excision repair; TagI, E. coli 3-methyladenine-DNA-glycosylase I; AlkA, E. coli 3-methyladenine-DNA-glycosylase II; UDG, E. coli uracil-DNA-glycosylase; Fpg, E. coli formamidopyrimidine-DNA glycosylase; Nth, E. coli endonuclease III; Nfo, E. coli endonuclease IV; MUG, mismatch-specific uracil-DNA glycosylase; ANPG, human alkylpurine-DNA N-glycosylase; APDG, rat ANPG; hOGG1, human 7,8-dihydro-8-oxoguanine-DNA glycosylase; hNth1, human endonuclease III; Ape1, human AP-endonuclease; hTDG, human thymine-DNA glycosylase; BSA, bovine serum albumin; FITC, fluorescein isothiocyanate; EMSA, electrophoretic mobility shift assay; SPR, surface plasmon resonance; dabcyl, 4-(4-dimethylaminophenyl-azo)benzoic acid; XPA and XPC, Xeroderma pigmentosum complementation group A and C. and nitric oxide overproduction, which target DNA bases forming genotoxic exocyclic adducts such as 1,N6-ethenoadenine (ϵA) and 3,N4-ethenocytosine (ϵC) (1Nair J. Barbin A. Guichard Y. Bartsch H. Carcinogenesis. 1995; 16: 613-617Crossref PubMed Scopus (228) Google Scholar, 2Chung F.L. Chen H.J. Nath R.G. Carcinogenesis. 1996; 17: 2105-2111Crossref PubMed Scopus (328) Google Scholar, 3Pollack M. Oe T. Lee S.H. Silva Elipe M.V. Arison B.H. Blair I.A. Chem. Res. Toxicol. 2003; 16: 893-900Crossref PubMed Scopus (79) Google Scholar). Etheno(ϵ)-adducts are also formed by reaction with epoxides that result from the metabolism of various industrial pollutants such as vinyl chloride and vinyl carbamate (4Barbin A. Mutat. Res. 2000; 462: 55-69Crossref PubMed Scopus (134) Google Scholar). E-adducts are ubiquitous, and highly variable background levels of ϵA and ϵC were found in asymptomatic tissue DNA under normal physiological conditions. It was shown that the level of ϵC present in 10 different human liver DNA samples averaged 28 ± 9 ϵC/108 bases (5Marnett L.J. Burcham P.C. Chem. Res. Toxicol. 1993; 6: 771-785Crossref PubMed Scopus (275) Google Scholar), whereas in leukocytes, pancreas, and colon DNA samples isolated from healthy volunteers, it ranged from 0.1 to 11 ϵC/108 parent bases (6Nair J. IARC Sci. Publ. 1999; 150: 55-61Google Scholar). Based on these numbers, we estimate that the molar concentration of ϵC within the nucleus in human cells ranges from 0.2 to 40 nm. The low density lipids that transport cholesterol in the bloodstream are extremely susceptible to oxidation (7Mertens A. Verhamme P. Bielicki J.K. Phillips M.C. Quarck R. Verreth W. Stengel D. Ninio E. Navab M. Mackness B. Mackness M. Holvoet P. Circulation. 2003; 107: 1640-1646Crossref PubMed Scopus (166) Google Scholar), and it was speculated that this may account for the highly variable background levels of ϵ-adducts found in the DNA from normal human tissues (1Nair J. Barbin A. Guichard Y. Bartsch H. Carcinogenesis. 1995; 16: 613-617Crossref PubMed Scopus (228) Google Scholar). The increasing interest in exocyclic DNA adducts has been triggered by the observation that they are highly mutagenic. During DNA replication in Escherichia coli and simian kidney cells, ϵC mostly produces ϵC·G to A·T transversions and ϵC·G to T·A transitions (8Basu A.K. Wood M.L. Niedernhofer L.J. Ramos L.A. Essigmann J.M. Biochemistry. 1993; 32: 12793-12801Crossref PubMed Scopus (204) Google Scholar, 9Moriya M. Zhang W. Johnson F. Grollman A.P. Proc. Natl. Acad. Sci. U. S. A. 1994; 91: 11899-11903Crossref PubMed Scopus (233) Google Scholar). In a single-stranded shuttle vector containing a single ϵC residue, the targeted mutation frequency yield was 81% in simian kidney cells (9Moriya M. Zhang W. Johnson F. Grollman A.P. Proc. Natl. Acad. Sci. U. S. A. 1994; 91: 11899-11903Crossref PubMed Scopus (233) Google Scholar). The ϵA residues are also highly mutagenic in mammalian cells, where they lead mainly to ϵA·T to T·A transversions (10Pandya G.A. Moriya M. Biochemistry. 1996; 35: 11487-11492Crossref PubMed Scopus (180) Google Scholar, 11Levine R.L. Yang I.Y. Hossain M. Pandya G.A. Grollman A.P. Moriya M. Cancer Res. 2000; 60: 4098-4104PubMed Google Scholar) but are weak mutagens in E. coli. Therefore, the processes preventing mutations caused by ϵ-adducts in the genome upon cell division should play a crucial role in maintaining the stability of the genetic information. When present in DNA, ϵC residues are eliminated by the base excision repair (BER) pathway initiated in human cells by mismatch-specific thymine-DNA glycosylase (hTDG) (12Saparbaev M. Laval J. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 8508-8513Crossref PubMed Scopus (164) Google Scholar, 13Hang B. Medina M. Fraenkel-Conrat H. Singer B. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 13561-13566Crossref PubMed Scopus (82) Google Scholar). However, excision efficiency of ϵC by hTDG is rather poor (12Saparbaev M. Laval J. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 8508-8513Crossref PubMed Scopus (164) Google Scholar). Recently, two additional enzymes that excise ϵC, have been identified in human cells: the methyl-CpG binding domain protein (MBD4/MED1) (14Petronzelli F. Riccio A. Markham G.D. Seeholzer S.H. Genuardi M. Karbowski M. Yeung A.T. Matsumoto Y. Bellacosa A. J. Cell. Physiol. 2000; 185: 473-480Crossref PubMed Scopus (89) Google Scholar) and single-strand monofunctional uracil-DNA glycosylase (SMUG1) (15Kavli B. Sundheim O. Akbari M. Otterlei M. Nilsen H. Skorpen F. Aas P.A. Hagen L. Krokan H.E. Slupphaug G. J. Biol. Chem. 2002; 277: 39926-39936Abstract Full Text Full Text PDF PubMed Scopus (280) Google Scholar). The human alkyl-N-purine-DNA glycosylase (ANPG) excises ϵA and a variety of damaged bases including alkylated purines, and but it does not excise ϵC in L. Laval J. 2002; PubMed Scopus (166) Google Scholar). and of ANPG have also been Laval F. J. PubMed Scopus Google Scholar, Chen Carcinogenesis. 1993; PubMed Scopus Google Scholar). suggest that ANPG could be of to cells and show increased to and such as and A. J. D. C. L. J. 1996; PubMed Scopus Google Scholar, G. J. I. J.M. B. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar). show a in mutations when with the B. M.C. Cell. Biol. 1998; PubMed Scopus Google Scholar). However, cells show to Cancer Res. 2002; Google Scholar), and cells of a to by A.P. Cell. Biol. PubMed Scopus Google Scholar). in cell to could be to ANPG The ANPG protein in normal human cells is in the nucleus as shown by 1998; PubMed Scopus Google Scholar). In human cells, ANPG could be present as including a P. P.C. Proc. Natl. Acad. Sci. U. S. A. 1993; PubMed Scopus Google Scholar, A. Carcinogenesis. 1994; PubMed Scopus Google Scholar, Laval J. Res. PubMed Scopus Google it has been that the to the and Res. 1993; PubMed Scopus Google Scholar). However, we have that the of ANPG are for glycosylase M. S. H. Laval J. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar). have that ANPG modified bases Based on ANPG was found to with a J. Laval J. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), and a complementation that it could with T. R. H. S. S. Proc. Natl. Acad. Sci. U. S. A. 1993; PubMed Scopus Google Scholar), the protein does not excise it has been shown that ANPG adducts in a reconstituted with and may these adducts from repair by the to M. Essigmann J.M. Biochemistry. 2000; PubMed Scopus Google Scholar). to measure the DNA glycosylase are and these we developed a based on molecular beacons containing modified bases that direct and DNA glycosylase in reconstituted systems and in cultured cells. The molecular is a single-stranded containing a to the target that is by and it a and a the S. 1996; PubMed Scopus Google Scholar). In the of the DNA these a in which the and are in to the fluorescence of the to be by fluorescence L. PubMed Scopus Google Scholar). Here, we report that excision of modified bases present in molecular by a DNA glycosylase be by in In the present a for of ANPG that the human and rat to ϵC residues present in either or single-stranded interaction ANPG and ϵC residues inhibits and glycosylase in the reconstituted Furthermore, a modified molecular we that containing a single ϵC inhibits ANPG in cultured human and cells. In the ϵC·ANPG complex inhibits both ϵC excision by hTDG and DNA by Klenow fragment in primer extension these results suggest that hijacking of ANPG in the ϵC·ANPG complex may lead to the of ϵC in and could result in replication The of the present observation is by the that hijacking of by DNA has been implicated in the of M. Essigmann J.M. Mutat. Res. PubMed Scopus Google Scholar) and the of in G. Biol. PubMed Scopus Google Scholar). Here, we a model of genotoxicity of the ϵC The of the ϵC·ANPG interaction for and genome instability are were from and including the ϵA, or or where is ϵA, ϵC, 8-oxoG, or molecular beacons, where is fluorescein and is acid; containing or to modified Molecular was a from Y. DNA, a modified was to and the are to as where is a modified The were used to the repair of ϵ-adducts and M. S. H. Laval J. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar, M. Laval J. Proc. Natl. Acad. Sci. U. S. A. 1994; 91: PubMed Scopus (233) Google Scholar). were by in the of and cells are from a human P. P. Laval F. DNA Biol. 1993; PubMed Scopus Google Scholar). and cells were in and in modified in a with were with serum and were as P. P. Laval F. DNA Biol. 1993; PubMed Scopus Google Scholar). of the E. coli glycosylase glycosylase uracil-DNA hTDG mismatch-specific thymine-DNA and was as M. S. H. Laval J. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar). of endonuclease and human endonuclease was as G. M. Res. 2003; PubMed Scopus Google Scholar). endonuclease protein was by R. The of the various was and was to of ϵA, ϵC, and residues was by the of containing a single a The for ϵC and excision 0.2 of the BSA, and of The reaction for ϵA excision was with were for hTDG, which was The were by for J. Biol. 1998; PubMed Scopus Google Scholar), and reaction were as G. M. Res. 2003; PubMed Scopus Google Scholar). The were to a and the of in the were The with molecular was with and a of in the reaction were in a and fluorescence was and with the was and was nm. was as the of the to the fluorescence of the reaction with that of the reaction of the reaction and the reaction were and and with nm. binding reaction of of and The was for on which was by on a for The were as of interaction were a in 10 was of a of was The of was found to be surface plasmon the containing ϵC was the surface as and different of were in low containing a the of the was by the of the and were DNA in and cells were in were two with and was by of of and of were in of A 10 and of were by to the cells, which were for and with a for in a fluorescence a double-stranded for DNA a containing either ϵC or was to a primer and a a molar by to for and The reaction 10 10 of and of Klenow were were for and were as of upon of a for of ANPG, we the glycosylase of ANPG in the of a containing base The ϵA·T was with protein in the or of a molar of the and not for shown in when ϵA·T is with by in to by ANPG, of the was of ϵA·T and a 9 and not However, molar of ϵA·T lead to a of ϵA excision The weak by ϵA·T and be to the of ANPG for these and M. Laval J. Res. 1995; PubMed Scopus Google Scholar, A. H. S. A. Y. Biochemistry. 2000; PubMed Scopus Google Scholar). on glycosylase of ANPG was in the of and molar and not and of the were in the of and molar of that ϵC is a more efficient than ϵA 10 and results were when the and rat were that the does not to the and that both the human and the rat ANPG a interaction with of were with which has different than that the ϵC·G is not Furthermore, the and glycosylase of ANPG were also in the of a and molar of ϵC·G and not the suggest that human and rat ANPG with ϵC residues DNA ANPG is the DNA glycosylase that ϵA residues in mammalian cells, we ϵC·G could ANPG in human as shown in the of cells inhibits ϵA excision 9 and and it was more efficient than ϵA·T A molar of A·T or on ϵA excision and result that ϵC when present in DNA, glycosylase in the of DNA to ϵC·G proposed that the of DNA glycosylase in the of ϵC·G could result from and binding of ANPG to Therefore, the interaction of with various was the binding a of and a of The E. coli and human are DNA (12Saparbaev M. Laval J. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 8508-8513Crossref PubMed Scopus (164) Google Scholar) as shown in in a highly with with more than of the DNA present in In under the not with However, in with the human and rat a complex with the enzymes UDG, Nth, Ape1, and not complex with and However, AlkA, Fpg, Nfo, hOGG1, and not excise ϵC, they were found to to and binding in to MUG, ANPG, and the interaction for AlkA, Fpg, Nfo, hOGG1, and was found to be rather not In the results show that the DNA repair MUG, and to ϵC in a of ANPG for the role of the of ANPG, the of various were The was under where shown in I, the of are from to nm. also binds to the ϵC containing single-stranded However, the to single-stranded was 10 than that for for ϵC·G and from and the ± of of ± ± ± ± ± from and the ± of of in a new of the the of the ϵC·ANPG to EMSA, the was and were and were the and the of binding and was shown in a in the was when was the In or binding was either when was with the or when was with the containing These results the of ϵC for by measure binding the level of on the was to to transport of the that the complex formed and is extremely and The was ± ± which is in with the and a and highly interaction ϵC and of by ANPG in we the that the interaction ANPG and ϵC ϵC from excision by and shown in inhibits of the ϵC·G by also inhibits thymine-DNA glycosylase of of glycosylase was also when was for and when was for not In these results that ANPG with ϵC and a complex that to the by DNA repair complex is formed the protein and the modified exocyclic base but not with the ANPG does not excise ϵC and It is also that ANPG with preventing the excision of ϵC ANPG also inhibits the glycosylase of E. coli of a DNA the present we used the fluorescence quenching mechanism of molecular beacons to a direct shown in we a single-stranded DNA containing with a and a in which the FITC, is in to the dabcyl, by the In a molecular the quenching efficiency of the is S. 1998; 16: PubMed Scopus Google Scholar). of in fluorescence of to not Molecular beacons a when they the either to a DNA target or S. 1996; PubMed Scopus Google Scholar, J. Zhang P. Cell. 2002; 16: PubMed Scopus Google Scholar). Here, for the we used the excision of residues by ANPG to base in the molecular and to the and the of with but not with E. coli or human Ape1, has lead to increased that the modified be used to measure glycosylase and not ANPG, we a containing either a single ϵC·G or a base In a reconstituted when present molar the the whereas the the glycosylase of of by ϵC in cells, molecular beacons S. 1996; PubMed Scopus Google Scholar). Here, we used molecular DNA glycosylase to the of ANPG by ϵC residues could in cultured mammalian cells. ANPG is the glycosylase in mammalian cells G. J. I. J.M. B. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar, B. Singer B. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google to measure with The a residue, and were human cells and and cells were fluorescence shown in or low level of fluorescence was in cells and in cells with in cells with the a These that were to the cells and that are in cultured cells A was in the cells with and with the that the molecular is and by glycosylase in cultured cells. In which the fluorescence background was in cells with and the were when cells these that glycosylase is in a by ϵC·G both in the reconstituted systems and in the cultured cells. of DNA by the ϵC·ANPG present in DNA, ϵC be by DNA D. D. Mutat. Res. 1994; PubMed Scopus Google Scholar, B. Singer B. Res. 2002; PubMed Scopus Google we speculated that ANPG to ϵC could DNA shown in a DNA containing either or ϵC·G base was used to the of on Klenow fragment DNA polymerase activity. of the primer to by Klenow fragment and to molar of on the ϵC·G Klenow and under the the of ϵC a weak for the DNA the reaction on the and a to the DNA polymerase was molar of of the is a that complex also by results were when not We also a of DNA on single-stranded ϵC molar of not These results demonstrate that binding of ANPG to ϵC the DNA polymerase activity. The of ϵ-adducts to human is by the that levels of ϵA and ϵC were increased by to such as and H. J. 2000; PubMed Scopus Google Scholar). The ϵ-adducts are in human cells by highly DNA L. M. Mutat. Res. 2003; PubMed Scopus Google Scholar). of ANPG, excises lesions by and such as and the of these The of the present was to of ANPG that be used to the cell efficiency of different various such as of EMSA, and SPR, we have shown that ANPG has a ϵC residues when present in double-stranded DNA. The has of for double-stranded and for single-stranded The and and ANPG have to ϵC, that the domain of ANPG is for ϵC of the and the molar concentration of ϵC in human cells that within the concentration of the ϵC·ANPG complex could the The of to a DNA containing ϵA have been L. T. Cell. 1998; 95: Full Text Full Text PDF PubMed Scopus Google Scholar, T. Proc. Natl. Acad. Sci. U. S. A. 2000; PubMed Scopus Google Scholar). is a single domain protein of which a group that does not protein T. A. T. Mutat. Res. 2000; PubMed Scopus Google Scholar). binding of ANPG to ϵC·G that the ϵC in the in to and hTDG, is not to excise the D. Johnson F. Grollman A.P. M. C. Biochemistry. PubMed Scopus Google Scholar, D. Johnson F. C. J. Biol. 2000; PubMed Scopus Google Scholar) have shown by that the ϵC the of However, these proposed that ANPG is not to the ϵC from DNA. Based on we suggest that ANPG is to ϵC from DNA, and we that it is the of in the of ANPG that results in to a In of this it has been that the of the base rather than the damaged base a crucial role in base excision by ANPG T. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The ϵC·ANPG interaction inhibits and glycosylase of ANPG and the excision of ϵC by and observation that the repair of ϵC in human cells be It is that the ϵC·ANPG to could be by DNA repair it has been that the and which are in the of DNA in excision repair J.M. C. T. A. A.P. S. C. A. Wood F. D. Cell. Biol. 17: PubMed Scopus Google Scholar), with ANPG and the of excision F. M. R. C. F. G. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). Therefore, the ϵC·ANPG complex may direct ϵC to the pathway by the complex to ϵC However, in have a interaction ANPG and and under the M. and J. Furthermore, the of ϵA adducts by vinyl carbamate in and does not from that of that pathway is not in the repair of The ϵC·ANPG complex inhibits in reconstituted that in cells, the repair of alkylated purines, and ϵA, also be the role of this interaction in cells, we have developed for the a direct DNA repair based on molecular containing modified which does not of the and which direct and to be both in reconstituted systems and in cells. a containing residues and with and was used as the for The was and cells, and the DNA excision of to of However, when and the were fluorescence was of the the on result that ϵC·ANPG complex may in mammalian cells under conditions. the of the ϵC·ANPG interaction on a DNA polymerase was primer extension We that binding of ANPG to or single-stranded DNA containing ϵC inhibits DNA by the E. coli Klenow fragment of DNA polymerase I. result that in ϵC residues could be more genotoxic than Therefore, hijacking of ANPG by ϵC residues could be of and the for this instability of the in is based on hijacking of the repair protein by DNA formed in the L. A. 1999; PubMed Scopus Google Scholar, PubMed Scopus Google the cell of DNA adducts by is by hijacking of the mobility group domain M. Essigmann J.M. Mutat. Res. PubMed Scopus Google the levels of ϵA by vinyl chloride and vinyl carbamate are than of ϵC S. IARC Sci. Publ. 1999; Google in the of ϵ-adducts by endogenous could be ϵC It has been that in a with a to colon ϵC levels were than in normal whereas ϵA was H. J. Cancer 2002; Full Text Full Text PDF PubMed Scopus Google in colon the level of ϵC was than that of ϵA H. J. Biol. Chem. 2002; PubMed Scopus Google Scholar). Recently, it has been shown that in is with increased level of ANPG, which in produces instability in various of cells in the tissue L.J. M. O. M. M. I. J. 2003; PubMed Scopus (180) Google Scholar). Based on these we that repair of ϵC may have biological In the results in the present demonstrate that ANPG has a role in the repair of It excises ϵA and 1,N2-ϵG, but the it the repair of ϵC by forming The suggest a of of damaged bases by a DNA glycosylase and mechanism by which the repair of ϵ-adducts be in mammalian cells. the genotoxicity of ϵC in be by hijacking of the DNA that increased endogenous could be extremely to human cells. It is to that oxidation of lipids in the bloodstream and in the colon tissues may lead to increased levels of ϵC, which in ANPG, and that this repair complex could in and in L.J. M. O. M. M. I. J. 2003; PubMed Scopus (180) Google Scholar, B. Y. Zhang D. M. G. D. I. Biol. 2003; PubMed Scopus Google Scholar). In the present may insight to molecular genotoxicity of LPO, which is to be a in a of human degenerative disorders. We for and Barbin for and to and and for of the with

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.