Genomic Identification of Significant Targets in Ciliochoroidal Melanoma

Purpose: To identify genomic targets for ciliochoroidal melanoma diagnosis, prognosis, and therapy.

Methods: Fifty-eight ciliochoroidal melanomas were analyzed by high-resolution, genome-wide, single nucleotide polymorphism (SNP) mapping arrays. The 58 SNP arrays were compared to 48 HapMap normals representing both sexes and assessed with a systematic statistical method, Genomic Identification of Significant Targets in Cancer (GISTIC), to identify significant ciliochoroidal chromosomal abnormalities including chromosome-arm-sized as well as focal events of amplification and deletion. The 58 SNP arrays were also analyzed to assess copy number.

Results: The 58 ciliochoroidal melanomas analyzed by GISTIC showed large regions of chromosome amplification on 6p and 8q in addition to focal amplification peaks on 1q31.3, 4p16.2, 9p23, and 9q33.1. The melanomas also showed large regions of deletion on 1p and all of 3, 6q, 8p, and 16q, as well as focal deletion peaks on 2p12, 2q14.3, 4q26, 5q21.1, 7q21.11, 8p21.3, 9p21.1, 13q21.31, 13q31.3, and 16q23.3. For each large region and focal peak, the statistical significance was computed, and known genes were specified.

Conclusions: High-resolution analysis of ciliochoroidal melanoma cytogenetic aberration patterns supports the utility of systematic characterization of the cancer genome by corroborating known melanoma-related genomic aberrations and identifying additional melanoma-related genomic abnormalities that can be used to identify potential targets for diagnosis, prognosis and therapy.