title: Regulation of the capacity for O6-methylguanine removal from DNA in human lymphoblastoid cells studied by cell hybridization.
abstract: Hybrids were made between a ouabain-resistant, thioguanine-resistant human lymphoma line able to remove O6-methylguanine from its DNA (Mex+) and human lymphoblastoid lines deficient in this capability (Mex-). The formation of hybrids was confirmed by chromosomal analysis. Hybrid cells had an O6-methylguanine removal capacity per mole of guanine about one third to one half that of the Mex+ parents, i.e., about the same per cell. Cell hybrids removed the same amount of the alkylation adduct 3-methyladenine as did their parents per mole of guanine, i.e., about twice as much per cell. Although the cell hybrids had intermediate resistance to the cytotoxic action of N-methyl-N'-nitro-N-nitrosoguanidine used to induce O6-methylguanine and 3-methyladenine, there is evidence that the ability to remove O6-methylguanine and resistance to the cytotoxic effect of N-methyl-N'-nitro-N-nitrosoguanidine are dissociable characteristics.
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D002459:Cell Fusion; D002460:Cell Line; D004247:DNA / Q000378:metabolism*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006822:Hybrid Cells; D007621:Karyotyping; D008223:Lymphoma; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009374:Neoplasms, Experimental
chemical_list: D008769:Methylnitronitrosoguanidine; C031080:3-methyladenosine; D004247:DNA; C015558:O(6)-methyl-2'-deoxyguanosine; D003849:Deoxyguanosine; D000241:Adenosine