Abstract 5352: Ultraviolet radiation induces carcinogenesis in a novel transgenic mouse model of melanoma

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Melanomagenesis is caused by environmental factors, such as ultraviolet (UV) radiation, as well as genetic factors. The Nucleotide Excision Repair (NER) pathway repairs photoproducts induced by UV radiation. In humans, NER pathway disruption leads to the development of skin cancers, including melanoma. Upon UV exposure, mice deficient in Xpc, an important protein in the NER pathway, develop skin cancer; but not melanoma. The Endothelin 3 (Edn3) signaling pathway is essential for melanocyte precursor cell development. In humans, this pathway has also been associated with melanoma progression and its metastatic potential. The purpose of this study is the development of a UV-dependent melanoma mouse model that combines Xpc deficiency with the over-activation of the Edn3 pathway. Transgenic mice over-expressing Edn3 under the control of the keratin 5 promoter (K5-Edn3) and carrying a targeted mutation in Xpc were exposed to a single suberythemal neonatal dose of UV radiation. Immunostaining and histomorphology were used to confirm the melanocytic origin of primary skin tumors. Melanomas were only found in animals with the K5-Edn3 transgene. High penetrance was observed in Xpc null (67%, n=3) and Xpc heterozygous (67%, n=3) mice in comparison to Xpc wild type (33%, n=3) mice. RNA extracted from melanomas of Xpc null (n=2), Xpc heterozygous (n=1) and Xpc wild type (n=1) mice were screened for UV signature mutations in Hras, Kras and Nras. No mutations were found in any of these genes. These results indicate that UV radiation exposure, in conjunction with over-activation of the Edn3 pathway is sufficient to lead to melanomagenesis in mice independently of mutations in Hras, Kras or Nras. Citation Format: Ana Paula Benaduce, Deannys Batista, Gabriel Grilo, Karen Jorge, Diana Cardero, Clara Milikowski, Lidia Kos. Ultraviolet radiation induces carcinogenesis in a novel transgenic mouse model of melanoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5352. doi:10.1158/1538-7445.AM2014-5352