Original Article
Keratinocytes/Epidermis
Genomic Characterization of Dysplastic Nevi Unveils Implications for Diagnosis of Melanoma

https://doi.org/10.1016/j.jid.2016.11.017Get rights and content
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A well-defined risk factor and precursor for cutaneous melanoma is the dysplastic nevus. These benign tumors represent clonal hyperproliferation of melanocytes that are in a senescent-like state, but with occasional malignant transformation events. To portray the mutational repertoire of dysplastic nevi in patients with the dysplastic nevus syndrome and to determine the discriminatory profiles of melanocytic nevi (including dysplastic nevi) from melanoma, we sequenced exomes of melanocytic nevi including dysplastic nevi (n = 19), followed by a targeted gene panel (785 genes) characterization of melanocytic nevi (n = 46) and primary melanomas (n = 42). Exome sequencing revealed that dysplastic nevi harbored a substantially lower mutational load than melanomas (21 protein-changing mutations versus >100). Known “driver” mutations in genes for melanoma, including CDKN2A, TP53, NF1, RAC1, and PTEN, were not found among any melanocytic nevi sequenced. Additionally, melanocytic nevi including dysplastic nevi showed a significantly lower frequency and a different UV-associated mutational signature. These results show that although melanocytic nevi and dysplastic nevi harbor stable genomes with relatively few alterations, progression into melanomas requires additional mutational processes affecting key tumor suppressors. This study identifies molecular parameters that could be useful for diagnostic platforms.

Abbreviations

CAN
common acquired nevus
CMN
congenital melanocytic nevus
DN
dysplastic nevus
DNS
dysplastic nevus syndrome

Cited by (0)

7

Present address: NeraCare GmbH, Boenen, Germany.

8

These authors contributed equally to this work and should be considered as senior coauthors.