APR 01, 2020
Ocular Pathology/Oncology
This study assessed the tumor microenvironment of uveal melanoma using single cell analysis.
Study design
The authors analyzed the tumor microenvironment using droplet-based single-cell RNA sequencing (scRNA-seq). They obtained 59,915 uveal melanoma cells and non-neoplastic cells from 8 primary and 3 metastatic uveal melanomas.
Outcomes
There was a diversity of tumor-infiltrating immune cells in the tumor microenvironment, including CD8+ T cells. These cells predominantly expressed the checkpoint marker LAG3 rather than PD1 or CTLA4, which are current targets for checkpoint blockades. This could explain, in part, why currently available checkpoint inhibitors are minimally efficacious for treating metastatic uveal melanoma. It also provides a potential new target for checkpoint blockage.
Limitations
The researchers analyzed a small number of primary tumors and metastases.
Clinical significance
This study identified LAG3 as a potential target for immune checkpoint blockade in patients with high risk uveal melanoma.