Minimal contribution of ERK1/2-MAPK signalling towards the maintenance of oncogenic GNAQQ209P-driven uveal melanomas in zebrafish.
Mutations affecting Gαq proteins are pervasive in uveal melanoma (UM), suggesting they 'drive' UM pathogenesis. The ERK1/2-MAPK pathway is critical for cutaneous melanoma development and consequently an important therapeutic target. Defining the contribution of ERK1/2-MAPK signalling to UM development has been hampered by the lack of an informative animal model that spontaneously develops UM. Towards this end, we engineered transgenic zebrafish to express oncogenic GNAQQ209P in the melanocyte lineage. This resulted in hyperplasia of uveal melanocytes, but with no evidence of malignant progression, nor perturbation of skin melanocytes. Combining expression of oncogenic GNAQQ209P with p53 inactivation resulted in earlier onset and even more extensive hyperplasia of uveal melanocytes that progressed to UM. Immunohistochemistry revealed only weak immunoreactivity to phosphorylated (p)ERK1/2 in established uveal tumours-in contrast to strong immunoreactivity in oncogenic RAS-driven skin lesions-but ubiquitous positive staining for nuclear Yes-associated protein (YAP). Moreover, no changes were observed in pERK1/2 levels upon transient knockdown of GNAQ or phospholipase C-beta (PLC-β) inhibition in the majority of human UM cell lines we tested harbouring GNAQ mutations. In summary, our findings demonstrate a weak correlation between oncogenic GNAQQ209P mutation and sustained ERK1/2-MAPK activation, implying that ERK1/2 signalling is unlikely to be instrumental in the maintenance of GNAQQ209P-driven UMs.
['Mouti|Mai Abdel|MA|', 'Dee|Christopher|C|', 'Coupland|Sarah E|SE|', 'Hurlstone|Adam F L|AF|']
D000818:Animals D030801:Animals, Genetically Modified D002273:Carcinogens D002460:Cell Line D019070:Cell Lineage D004251:DNA Transposable Elements D048049:Extracellular Signal-Regulated MAP Kinases D020869:Gene Expression Profiling D005786:Gene Expression Regulation D016158:Genes, p53 D006801:Humans D007150:Immunohistochemistry D020935:MAP Kinase Signaling System D008544:Melanocytes D009154:Mutation D015398:Signal Transduction D014604:Uveal Neoplasms D015027:Zebrafish
uveal melanoma zebrafish p53 GNAQ ERK1/2