Cutaneous and uveal melanoma: two different cancers in therapeutic needs.

Melanocytes are located in various parts of the human body, such as the skin and the eye. Their transformation leads to melanoma, an aggressive and deadly neoplasm. Cutaneous and uveal melanomas show different characteristics, including significant differences in genetic alterations, metastatic sites and therapeutic response. In recent decades, great efforts have been made to obtain a more comprehensive understanding of genetics, genomics and molecular changes, enabling the identification of key cellular processes and signaling pathways in melanomas. Major breakthroughs were realized in the treatment of metastatic cutaneous melanoma, but most patients relapse. Currently, there is no approved systemic treatment for metastatic uveal melanoma. Thus, these two different cancers are in therapeutic need to overcome treatment failure and improve patient prognosis. In this review we discuss on one hand the mutation of MITF, the master gene of melanocyte homeostasis, which we identified as a new melanoma predisposition gene in cutaneous melanoma, and on the other hand the recent findings of intratumor heterogeneity and characterization of cell sub-populations in primary uveal melanomas. These studies offer new tools for early detection and therapeutic targets.