Figure 4

TRAIL expressing mice develop less preneoplastic lesions compared to wild-type animals. (A) Representative images of the histologic structure of the lesions provoqued by the treatment. DMBA/TPA treated mice develop three different types of lesions: hamartomas, trichofolliculomas and papillomas, the two first being benign whereas the last one is a preneoplastic lesion. Bar, 400 μm. (B) Representative immunofluorescence images of hamartoma and papilloma lesions stained with Keratin 1 and α6 integrin. Bar, 100 μm. (C) Percentage of benign versus preneoplastic lesions in TRAIL transgenic mice compared to wild-type mice. The difference observed between wild-type and TRAIL transgenic lesions is highly significant (P < 0.0001), as determined by Fisher's exact test. (D) Western blot analysis of wild type and transgenic tumor samples using antibodies against two transformation markers, inactivated GSK3 phosphorylated at Ser9 and β-catenin. Actin is used as a loading control.