Novel uveal Melanocyte cell lines display distinct features from uveal melanoma.

Purposes: Despite advances in prognostication for uveal melanoma (UM), mortality from this disease remains high due to a lack of effective treatments to prevent metastatic progression. Novel therapeutic targets are needed, but few studies have been able to compare UM to its progenitor cell due to a lack of commercially available uveal melanocyte cell lines. We established novel uveal melanocyte cell lines for comparison to our novel UM patient-derived organoids (PDOs). Methods: Uveal melanocytes were isolated from the choroid of post-mortem donor eyes. Melanocytes were cultured in Ham's F12 medium, and melanocytic markers were confirmed using immunohistochemistry. Melanocytes were grown as spheroids on Cultrex-coated plates prior to Exome- and RNA-sequencing for comparison to UM PDOs. Results: Uveal melanocytes were successfully established with confirmed melanocytic markers and absence of contaminant cell types. Melanocytes displayed regular, higher order growth patterns in 2D culture compared to more primitive colony formation displayed by UM, and melanocytes could be carried for at least 15 passages. Exome-sequencing confirmed an absence of UM-relevant mutations in the melanocytes, and RNA-sequencing revealed differential gene expression between benign uveal melanocytes and UM PDOs. Conclusions: Well-characterized uveal melanocyte cell lines can be compared to UM samples in the laboratory to help identify novel UM treatment targets and serve as a control population for future translation research.