Table 4.

Immunohistochemical Analysis of β-Catenin and Mutation Spectrum of β-Catenin Gene in Tumors Induced by PhIP

Sample no.	Type*	Exp. Periods (weeks)	β-Catenin accumulation		Mutation spectrum
			Cytoplasm†	Nucleus‡	Codon	Type of mutation	AA substitution
1	Ad	25	+	+	34	GGA → GAA	Gly → Glu
2	AdC	25	++	++	34	GGA → GTA	Gly → Val
3	AdC	32	++	++	36	CAC → CCC	His → Pro
					38	GGT → CGT	Gly → Arg
4	AdC	32	++	++	32	GAT → AAT	Asp → Asn
5	AdC	32	++	++
6	AdC	32	++	++	34	GGA → GTA	Gly → Val

* Ad, adenoma; AdC, adenocarcinoma.

^† +, weakly stained; ++, densely stained.

^‡ +, The nuclei in a few cells were stained; ++, the nuclei in most cells were stained.