FIG 4.

The Myc 3′ WRE controls proliferation but not apoptosis in the colons of Apc^Min/+ mice. (A) Ki67- and cleaved caspase 3 (CASP3)-stained sections of preneoplastic colons and colonic tumors from Apc^Min/+ (top) and Apc^Min/+ Myc 3′ WRE^−/− (bottom) mice. Representative images are shown (n = 4 mice analyzed per genotype). Arrowheads indicate CASP3⁺ cells. (B) Quantification of Ki67⁺ (left) and CASP3⁺ (right) cells in preneoplastic colons of Apc^Min/+ and Apc^Min/+ Myc 3′ WRE^−/− mice (n = 4 mice analyzed, with cells counted in a total of 100 crypts per genotype). (C) Same as panel B except that Ki67⁺ and CASP3⁺ cells were analyzed in tumor sections prepared from mice with the indicated genotypes (n = 4 mice, with 40 fields of view examined per genotype). In panels B and C, errors are standard errors of the means (**, P < 0.01; ***, P < 0.001).