Potential of Aqueous Humor as a Liquid Biopsy for Uveal Melanoma

oleh: Deborah H. Im, Chen-Ching Peng, Liya Xu, Mary E. Kim, Dejerianne Ostrow, Venkata Yellapantula, Moiz Bootwalla, Jaclyn A. Biegel, Xiaowu Gai, Rishvanth K. Prabakar, Peter Kuhn, James Hicks, Jesse L. Berry

Format: Article
Diterbitkan: MDPI AG 2022-06-01

Deskripsi

Tumor biopsy can identify prognostic biomarkers for metastatic uveal melanoma (UM), however aqueous humor (AH) liquid biopsy may serve as an adjunct. This study investigated whether the AH of UM eyes has sufficient circulating tumor DNA (ctDNA) to perform genetic analysis. This is a case series of 37 AH samples, taken before or after radiation, and one tumor wash sample, from 12 choroidal and 8 ciliary body (CB) melanoma eyes. AH was analyzed for nucleic acid concentrations. AH DNA and one tumor wash sample underwent shallow whole-genome sequencing followed by Illumina sequencing to detect somatic copy number alterations (SCNAs). Four post-radiation AH underwent targeted sequencing of <i>BAP1</i> and <i>GNAQ</i> genes. Post-radiation AH had significantly higher DNA and miRNA concentrations than paired pre-radiation samples. Highly recurrent UM SCNAs were identified in 0/11 post-radiation choroidal and 6/8 post-radiation CB AH. SCNAs were highly concordant in a CB post-radiation AH with its matched tumor (r = 0.978). <i>BAP1</i> or <i>GNAQ</i> variants were detected in 3/4 post-radiation AH samples. AH is a source of ctDNA in UM eyes, particularly in post-radiation CB eyes. For the first time, UM SCNAs and mutations were identified in AH-derived ctDNA. Suggesting that AH can serve as a liquid biopsy for UM.