Gene expression profile analysis of inducible melanotic and amelanotic melanoma in mice

We analyzed an inducible melanoma model in TiRP Ink4a/ArfF/F B10.D2 mice based on the conditional deletion in melanocytes of two tumor suppressor genes INK4a/Arf coupled to the expression of the oncogene H-rasG12V and a known tumor antigen (Hujibers et al. Cancer Res. 66:3278,2006; Soudja et al. Cancer Res. 70:3515-3525,2010). About 40% of these mice develop melanomas. Some tumors are heavily pigmented melanotic melanoma and grow slowly (hereafter referred to as “Mela”), but most of the induced tumors are nonpigmented amelanotic melanomas which are more aggressive (hereafter referred to as “Amela”). Gene expression profiles of the two types of tumors and of Amela-derived cell lines established in vitro were analyzed to identify the transcriptional signatures of these two types of tumors (including stromal components and infiltrating cells), as well as that intrinsic to Amela-tumor cells. 4 Amela and 4 Mela ex-vivo tumors were compared in a dye-swap experiment (8 chips). 4 Amela and 4 Mela ex-vivo tumors were compared to healthy skin (CTRL) (8 chips). 4 Amela ex-vivo tumors and Amela cell lines were compared in a dye-swap experiment (8 chips).