o-Aminoazotoluene, 7,12-dimethylbenz[a]anthracene, and N-ethyl-N-nitrosourea, which are mutagenic but not carcinogenic in the colon, rapidly induce colonic tumors in mice with dextran sulfate sodium-induced colitis

Table 2 Multiplicity of colonic dysplastic foci and tumors induced by a CMNC in combination with DSS

Treatment	Dysplasia	Adenoma	Adenocarcinoma	Tumor^a
Non-treatment	0 ± 0	0 ± 0	0 ± 0	0 ± 0
Vehicle^b + 4% DSS	0 ± 0	0 ± 0	0 ± 0	0 ± 0
AAT (125 mg/kg/day)	0 ± 0	0 ± 0	0 ± 0	0 ± 0
AAT (125 mg/kg/day) + 4% DSS	0.9 ± 0.6***	3.8 ± 1.2***	4.1 ± 1.7***	7.9 ± 2.0***
DMBA (25 mg/kg/day)	0 ± 0	0 ± 0	0 ± 0	0 ± 0
DMBA (25 mg/kg/day) + 4% DSS	1.0 ± 1.1**	1.5 ± 2.0*	1.5 ± 1.6**	3.0 ± 1.9***
ENU (11 mg/kg/day)	0 ± 0	0 ± 0	0 ± 0	0 ± 0
ENU (11 mg/kg/day) + 4% DSS	1.6 ± 0.5***	4.9 ± 1.9***	3.7 ± 1.5***	8.6 ± 1.1***

Multiplicity indicates the number of dysplasias, adenomas, or adenocarcinomas per mouse, mean ± standard deviation
CMNC; colon-mutagenic non-carcinogen
^a: adenoma + adenocarcinoma
^b: water for injection for 7 mice and salad oil for 6 mice
*, **, ***; significantly different from the DSS alone group at P < 0.1, 0.05, 0.01 in the Welch’s t-test

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