Melanoma evolution in MeLiM minipigs

In MeLiM minipigs, melanomas develop around birth, can metastasise and have histopathologic characteristics similar to humans. Interestingly, MeLiM melanomas can eventually regress and depigment. This favourable outcome raises the issue of their malignancy, which we investigated. We show a dynamic infiltration of immune cells into nodular tumors between the first 12 days of age (Early Progression=EP) and subsequent ones (Progression=P), even when the later showed histological signs of fibrosis (Progression with Fibrosis=PF). Some animals die of melanoma. Transcriptome analysis on cutaneous lesions revealed that all cancer hallmarks are found enriched in MeLiM melanomas at all stages.