Severe follicular hyperplasia and spontaneous papilloma formation in transgenic mice expressing theneu oncogene under the control of the bovine keratin 5 promoter

Transgenic mice expressing the neu oncogene under the bovine keratin 5 promoter were studied to understand erbB2's role in epithelial homeostasis and tumorigenesis. The mice exhibited visibly thickened skin, patchy hair growth, and significant epidermal hyperplasia, with some areas resembling squamous cell carcinoma. Abnormal proliferation of sebaceous glands and other epithelial tissues was observed, along with hyperkeratosis in the forestomach and esophagus, and increased lymphocyte cell death in the thymus. The study concluded that erbB2 signaling played a crucial role in epidermal proliferation and carcinogenesis in mouse skin.