The vinyl monomer acrylamide is characterized by the presence of an a,b-unsaturated carbonyl groupthat makes it reactive towards thiol, hydroxyl or amino groups and towards the nucleophilic centersin DNA. The ability of acrylamide to chemically modify protein thiols has prompted us to consider topoisomeraseII as one possible target of acrylamide, since agents targeting protein sulfhydryl groups act aseither catalytic inhibitors or poisons of topoisomerase II. Nuclear extracts from V79 Chinese hamster cellsincubated with acrylamide reduced topoisomerase II activity as inferred by an inability to convert kinetoplastDNA to the decatenated form. Nuclear extracts incubated with acrylamide pre-incubated withDTT converted kinetoplast DNA to the decatenated form, suggesting that acrylamide influences topoisomeraseII activity through reaction with sulfhydryl groups on the enzyme. Furthermore, acrylamide didnot induce the pBR322 DNA cleavage, as assessed by cleavage assay; thus, it cannot be regarded as a poisonof topoisomerase II. As a catalytic inhibitor, acrylamide antagonizes the effect of etoposide, a topoisomeraseII poison, as determined by clonogenic assay in V79 cells. This antagonism is confirmed by banddepletion assay, from which it can be inferred that acrylamide reduces the level of catalytically active cellulartopoisomerase II available for the action of etoposide.
|Numero di pagine||5|
|Rivista||Toxicology in Vitro|
|Stato di pubblicazione||Published - 2010|
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