Table 1.

The mean levels of 3-(2-deoxy-β-D-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M₁dG) adducts, expressed as relative adduct labelling (RAL × 10⁶), and the average amounts of oxidative lesions, expressed as relative intensity (RI), at the TP53 level in the MDA-MB23 oestrogen receptor-negative breast cells treated with increased concentrations of the xanthine plus xanthine oxidase system

	Genomic DNA			Oxidative lesions along the coding strand of the exon 5 of the human TP53 gene
	M1dG			Codon 163 (-TAC-)		Codon 170 (-ACG-)		Codon 173 (-GTG-)		Codon 175 (-CGC-)
	N	RAL ± s.e.	P-value	RI ± s.e.	P-value	RI ± s.e.	P-value	RI ± s.e.	P-value	RI ± s.e.	P-value
Experimental dosages
Controlsa	10	0.38 ± 0.10		0.08 ± 0.02		0.06 ± 0.01		0.10 ± 0.03		0.11 ± 0.03
0.2 mM xanthine, 1.0 mU xanthine oxidase	10	1.89 ± 0.10	0.016	0.10 ± 0.02	0.214	0.40 ± 0.07	0.016	0.18 ± 0.03	0.114	0.19 ± 0.03	0.164
0.2 mM xanthine, 5.0 mU xanthine oxidase	10	2.87 ± 0.59	0.007	0.22 ± 0.03	0.004	0.55 ± 0.08	0.004	0.44 ± 0.07	0.005	0.28 ± 0.04	0.014
P-value for trend			<0.001		0.001		<0.001		0.001		0.012

^aReference level.