Researchers at Moffitt Cancer Center have developed a new laboratory model that may significantly advance research into uveal melanoma, the most common form of ocular melanoma in adults. The findings, published in Cancer Research, introduce a more realistic mouse model that replicates how the disease develops and progresses in human patients.
Uveal melanoma begins in the uvea, the pigmented layer of tissue located between the retina and the outer wall of the eye. Although the cancer originates in the eye, it spreads to other parts of the body in about 50% of patients, most commonly the liver. Once metastasis occurs, treatment options remain limited, making research into disease progression critically important.
Until now, many existing animal models have failed to accurately reproduce how ocular melanoma develops in humans. Previous models often relied on a single genetic mutation, which resulted in tumors forming too quickly and without the additional biological changes typically seen in patients.
The new model created by Moffitt researchers takes a step-by-step genetic approach that mirrors what occurs in real cases of uveal melanoma. Scientists first introduced a mutation in the GNAQ gene, which is commonly found in patients and initially produces benign eye lesions. When researchers removed the BAP1 tumor-suppressor gene, the likelihood of those lesions progressing to cancer increased. Finally, activating the MYC gene caused the tumors to become significantly more aggressive and closely resemble human uveal melanoma.
One of the most important discoveries from the study is that cancer cells can shift between different biological states. Some tumor cells retain characteristics of normal pigment-producing cells, while others transform into aggressive forms associated with poor outcomes. This flexibility may help explain why uveal melanoma can become more dangerous over time.
The model also reproduces the immune microenvironment found in patients with ocular melanoma. Tumors contained immune cells that were present but largely ineffective, which may explain why traditional immunotherapies have shown limited success in treating this disease.
Researchers also identified molecular biomarkers linked to aggressive tumors, which may help doctors better assess patient risk and guide treatment strategies in the future.
By closely replicating the biology of human ocular melanoma, this new model could help scientists better understand how the disease spreads, particularly why metastasis often targets the liver. Ultimately, it may accelerate the development of new targeted therapies and immunotherapies designed specifically for patients with uveal melanoma.