Uveal melanoma driver mutations in GNAQ/11 yield numerous changes in melanocyte biology

Uveal melanoma (UM) is the most common primary intraocular cancer and has a high incidence of metastasis, which lacks any effective treatment. Here, we present-zebrafish models of UM, which are driven by melanocyte-specific expression of activating GNAQ or GNA11 alleles, GNAQ/11(Q209L), the predominant initiating mutations for human UM. When combined with mutant tp53, GNAQ/11(Q209L) transgenics develop various melanocytic tumors, including UM, with near complete penetrance. These tumors display nuclear YAP localization and thus phenocopy human UM. We show that GNAQ/11(Q209L) expression induces profound melanocyte defects independent of tp53 mutation, which are apparent within 3 days of development. First, increases in melanocyte number, melanin content, and subcellular melanin distribution result in hyperpigmentation. Additionally, altered melanocyte migration, survival properties, and evasion of normal boundary cues lead to aberrant melanocyte-localization and stripe patterning. Collectively, these data show that GNAQ/11(Q209L) is sufficient to induce numerous protumorigenic changes within melanocytes.