A murine model of squamous intraepithelial neoplasia

Focal areas of intraepithelial neoplasia were induced in the skin of mice by 1 intraperitoneal injection of urethane followed by twice weekly topical applications of 12-0-tetra-decanoyl phorbol-13-acetate (TPA). Microscopic lesions with histologic characteristics of intraepithelial neoplasia were seen in all animals after 11 weeks of TPA application. Fluorescence microscopy verified the increased DNA content of these lesions. This easily produced animal model of premalignant disease might be valuable in the preclinical testing of topically applied antineoplastic agents.