Skin-Specific Expression of a Truncated E1a Oncoprotein Binding to p105-Rb Leads to Abnormal Hair Follicle Maturation Without Increased Epidermal Proliferation

The study examined the impact of a mutant Adenovirus E1a oncoprotein, NTdl646, on skin cells in transgenic mice, revealing that its expression led to abnormal hair follicle maturation, characterized by short, crooked hair shafts and a dystrophic or absent inner root sheath. Despite these hair follicle abnormalities, the surrounding skin remained normal, and there was no increase in skin tumors. The keratinocytes in these mice showed partial resistance to growth inhibitors, suggesting that the oncoprotein disrupted normal hair follicle development by interfering with growth regulatory proteins, without causing cancerous growth.