Mutation Spectrum Induced by 8-Bromoguanine, a Base Damaged by Reactive Brominating Species, in Human Cells

Figure 1

Induction of mutations by 8-bromoguanine (8BrG) in human cells. (a) Comparison of the mutation frequency of the supF gene in the pMY189 plasmid using a supF forward mutation assay in the human H1299, LN428, and 16HBE14o- cell lines. The mutation frequency was compared between wild-type pMY189 and 8BrG-containing pMY189, which has an 8BrG residue at position 159 of supF. The data are shown as the means ± standard error. (b) Frequency of mutant colonies containing a base substitution mutation or one-base deletion mutation at position 159 of supF on wild-type pMY189 and/or 8BrG-containing pMY189 in a supF forward mutation assay in H1299, LN428, and 16HBE14o- cells. The total number of mutant colonies that were analyzed is shown in parentheses. (c) Representative results of supF mutations in 8BrG-containing pMY189 plasmids replicated in H1299 cells. Sequencing electropherograms show a G → T, G → C, delG, or G → A mutation at position 159 of the supF. A mutated site and a deleted site were marked by an asterisk and “V,” respectively. The leftmost is the wild-type supF sequence. (d) Proportion of mutation types detected at position 159 of supF on 8BrG-containing pMY189 plasmids replicated in H1299, LN428, and 16HBE14o- cells. The total number of mutations at position 159 of supF is shown in parentheses.

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