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Updated: Sep 22, 2025
A Robust Discovery Platform for the Identification of Novel Mediators of Melanoma Metastasis
Published on: March 8, 2022
Dysplastic nevi and melanoma: microRNAs tell a divergent story
Giorgio Durante1, Giulia Veronesi2, Cosimo Misciali2
1Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna 40100, Italy.
Background:
dysplastic nevi (DN) share some clinical and histological features with melanoma and have been considered intermediate lesions toward malignant transformation. However, scientific evidence of DN representing melanoma precursors is still incomplete, and many observations pointed toward their being a distinct biological entity. The current definition of DN is also confusing and the practical consequence of this uncertainty is the excessive excision of DN with severe atypia. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and whose global expression can classify normal and pathological tissues.
Objectives:
given these considerations, we decided to perform a small RNA profiling study in a group of DN and invasive melanomas obtained from the same patient, to assess tumor evolution according to the global microRNA expression.
Methods:
we performed a small-RNA sequencing of 6 DN, 2 congenital nevi and 4 cutaneous melanomas obtained from 4 subjects and evaluated the global miRNA expression correlation between samples.
Results And Conclusions:
the hierarchical clustering and principal component analyses of global miRNA expression, independently grouped together DN and their matching congenital nevi and showed a divergence of DN miRNA profile from melanoma. Our study suggests that DN have a peculiar and different miRNA expression profile compared to melanomas developed in the same patient, thus supporting the hypothesis that DN are distinct biological entities and not melanoma precursors.
Insights
Dysplastic nevi (DN) have a distinct microRNA (miRNA) expression profile, separate from melanoma. This suggests dysplastic nevi are unique biological entities, not precursors to melanoma.
Area of Science:
- Molecular biology
- Dermatology
- Oncology
Background:
- Dysplastic nevi (DN) share features with melanoma, but their role as precursors is debated.
- Uncertainty leads to excessive excision of DN with severe atypia.
- MicroRNAs (miRNAs) are key regulators of gene expression and can classify tissue types.
Purpose of the Study:
- To investigate tumor evolution by comparing global microRNA expression in DN and invasive melanomas from the same patient.
- To assess if DN represent distinct biological entities or melanoma precursors.
Main Methods:
- Small-RNA sequencing was performed on 6 DN, 2 congenital nevi, and 4 cutaneous melanomas from 4 subjects.
- Global miRNA expression correlation between samples was evaluated.
Main Results:
- Hierarchical clustering and principal component analyses grouped DN and their matching congenital nevi separately from melanomas.
- DN exhibited a distinct miRNA expression profile compared to melanomas from the same patient.
Conclusions:
- Dysplastic nevi possess a unique miRNA expression profile, differentiating them from melanomas.
- Findings support the hypothesis that DN are distinct biological entities, not melanoma precursors.
- This research may inform clinical decisions regarding the management of dysplastic nevi.
