Molecular alterations at chromosome 9p21 in melanocytic naevi and melanoma

M. C. Sini, A. Manca, A. Cossu, M. Budroni, G. Botti, P. A. Ascierto, F. Cremona, A. Muggiano, S. D'Atri, M. Casula, P. Baldinu, G. Palomba, A. Lissia, F. Tanda, G. Palmieri

Research output: Contribution to journalArticlepeer-review


Background: The chromosome 9p21 and its CDKN locus, with the p16 tumour suppressor gene (CDKN2A), are recognized as the genomic regions involved in the pathogenesis of melanoma. Objectives: To elucidate further the role of such regions during the different phases of melanocytic tumorigenesis. Methods: Tissue sections from naevi, primary and metastatic melanomas were investigated by fluorescence in situ hybridization for allelic loss at the 9p21 chromosome and by immunochemistry for p16CDKN2A expression. Results: Dysplastic naevi and primary or secondary melanomas were found to carry hemizygous deletions within the entire 9p21 region at similar frequencies (varying from 55% to 62%). Allelic deletion spanning the CDKN locus was observed at significantly increased rates moving from early (7%) to advanced (28%) primary melanomas and to secondary melanoma lesions (37%) (P = 0.018). Also, inactivation of the p16 gene (CDKN2A) was absent in naevi and present at steadily increasing rates moving from primary melanomas (7% early lesions to 17% advanced lesions) to melanoma metastases (62%) (P = 0.004). Conclusions: Our findings indicate that, in a model of sequential accumulation of genetic alterations, 9p21 deletions may play a role in melanocytic transformation and tumour initiation whereas rearrangements at the CDKN locus, and p16 gene (CDKN2A) inactivation may contribute to tumour progression.

Original languageEnglish
Pages (from-to)243-250
Number of pages8
JournalBritish Journal of Dermatology
Issue number2
Publication statusPublished - Feb 2008


  • Chromosome 9p21
  • FISH analysis
  • Melanomagenesis
  • p16 protein expression

ASJC Scopus subject areas

  • Dermatology


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