Animal Models of Uveal Melanoma: Methods, Applicability, and Limitations.

Animal models serve as powerful tools for investigating the pathobiology of cancer, identifying relevant pathways, and developing novel therapeutic agents. They have facilitated rapid scientific progress in many tumor entities. However, for establishing a powerful animal model of uveal melanoma fundamental challenges remain. To date, no animal model offers specific genetic attributes as well as histologic, immunologic, and metastatic features of uveal melanoma. Syngeneic models with intraocular injection of cutaneous melanoma cells may suit best for investigating immunologic/tumor biology aspects. However, differences between cutaneous and uveal melanoma regarding genetics and metastasis remain problematic. Human xenograft models are widely used for evaluating novel therapeutics but require immunosuppression to allow tumor growth. New approaches aim to establish transgenic mouse models of spontaneous uveal melanoma which recently provided preliminary promising results. Each model provides certain benefits and may render them suitable for answering a respective scientific question. However, all existing models also exhibit relevant limitations which may have led to delayed research progress. Despite refined therapeutic options for the primary ocular tumor, patients' prognosis has not improved since the 1970s. Basic research needs to further focus on a refinement of a potent animal model which mimics uveal melanoma specific mechanisms of progression and metastasis. This review will summarise and interpret existing animal models of uveal melanoma including recent advances in the field.