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dc.contributor.authorHarris, L C
dc.contributor.authorMargison, Geoffrey P
dc.date.accessioned2010-06-03T14:34:34Z
dc.date.available2010-06-03T14:34:34Z
dc.date.issued1993-06
dc.identifier.citationExpression in mammalian cells of the Escherichia coli O6 alkylguanine-DNA-alkyltransferase gene ogt reduces the toxicity of alkylnitrosoureas. 1993, 67 (6):1196-202 Br. J. Canceren
dc.identifier.issn0007-0920
dc.identifier.pmid8512805
dc.identifier.urihttp://hdl.handle.net/10541/100212
dc.description.abstractV79 Chinese hamster cells expressing either the O6-alkylguanine-DNA-alkyltransferase (ATase) encoded by the E. coli ogt gene or a truncated version of the E. coli ada gene have been exposed to various alkylnitrosoureas to investigate the contribution of ATase repairable lesions to the toxicity of these compounds. Both ATases are able to repair O6-alkylguanine (O6-AlkG) and O4-alkylthymine (O4-AlkT) but the ogt ATase is more efficient in the repair of O4-methylthymine (O4-MeT) and higher alkyl derivatives of O6-AlkG than is the ada ATase. Expression of the ogt ATase provided greater protection against the toxic effects of the alkylating agents then the ada ATase particularly with N-ethyl-N-nitrosourea (ENU) and N-butyl-N-nitrosourea (BNU) to which the ada ATase expressing cells were as sensitive as parent vector transfected cells. Although ogt was expressed at slightly higher levels than the truncated ada in the transfected cells, this could not account for the differential protection observed. For-N-methyl-N-nitrosourea (MNU) the increased protection in ogt-transfected cells is consistent with O4-MeT acting as a toxic lesion. For the longer chain alkylating agents and chloroethylating agents, the protection afforded by the ogt protein may be a consequence of the more efficient repair of O6-AlkG, O4-AlkT or both of these lesions in comparison with the ada-encoded ATase.
dc.language.isoenen
dc.subject.meshAnimals
dc.subject.meshBacterial Proteins
dc.subject.meshBase Sequence
dc.subject.meshCell Survival
dc.subject.meshClone Cells
dc.subject.meshCricetinae
dc.subject.meshDrug Resistance
dc.subject.meshEscherichia coli
dc.subject.meshFibroblasts
dc.subject.meshGene Expression
dc.subject.meshGuanine
dc.subject.meshLung
dc.subject.meshMethyltransferases
dc.subject.meshMolecular Sequence Data
dc.subject.meshMutagenesis, Site-Directed
dc.subject.meshNitrosourea Compounds
dc.subject.meshO(6)-Methylguanine-DNA Methyltransferase
dc.subject.meshThymine
dc.subject.meshTransfection
dc.titleExpression in mammalian cells of the Escherichia coli O6 alkylguanine-DNA-alkyltransferase gene ogt reduces the toxicity of alkylnitrosoureas.en
dc.typeArticleen
dc.contributor.departmentCRC Department of Carcinogenesis, Paterson Institute for Cancer Research, Christie Hospital, Manchester, UK.en
dc.identifier.journalBritish Journal of Canceren
html.description.abstractV79 Chinese hamster cells expressing either the O6-alkylguanine-DNA-alkyltransferase (ATase) encoded by the E. coli ogt gene or a truncated version of the E. coli ada gene have been exposed to various alkylnitrosoureas to investigate the contribution of ATase repairable lesions to the toxicity of these compounds. Both ATases are able to repair O6-alkylguanine (O6-AlkG) and O4-alkylthymine (O4-AlkT) but the ogt ATase is more efficient in the repair of O4-methylthymine (O4-MeT) and higher alkyl derivatives of O6-AlkG than is the ada ATase. Expression of the ogt ATase provided greater protection against the toxic effects of the alkylating agents then the ada ATase particularly with N-ethyl-N-nitrosourea (ENU) and N-butyl-N-nitrosourea (BNU) to which the ada ATase expressing cells were as sensitive as parent vector transfected cells. Although ogt was expressed at slightly higher levels than the truncated ada in the transfected cells, this could not account for the differential protection observed. For-N-methyl-N-nitrosourea (MNU) the increased protection in ogt-transfected cells is consistent with O4-MeT acting as a toxic lesion. For the longer chain alkylating agents and chloroethylating agents, the protection afforded by the ogt protein may be a consequence of the more efficient repair of O6-AlkG, O4-AlkT or both of these lesions in comparison with the ada-encoded ATase.


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