The human promyelocytic leukemia protein is a tumor suppressor for murine skin carcinogenesis

The study investigated the role of the human promyelocytic leukemia (PML) protein as a tumor suppressor in murine skin carcinogenesis. Transgenic mice overexpressing PML in the epidermis and hair follicles showed increased expression of keratin 10 and developed extensive alopecia as they aged. When subjected to skin tumor induction, these mice exhibited a 35% reduction in papilloma multiplicity and size, and a delay in the conversion of papillomas to carcinomas. Cultured transgenic keratinocytes displayed premature senescence and upregulated p16 and Rb transcripts. These findings suggested that PML played a role in regulating keratinocyte growth and differentiation, contributing to its tumor-suppressing activity.