NT5E (CD73) is epigenetically regulated in malignant melanoma and associated with metastatic site specificity
Author(s)
Type
Journal Article
Abstract
Background:
Novel prognostic biomarkers and therapeutic strategies are urgently required for malignant melanoma. Ecto-5-prime-nucleotidase (NT5E; CD73) overexpression has been reported in several human cancers. The mechanism(s) underlying deregulated expression and the clinical consequences of changes in expression are not known.
Methods:
We used RT–PCR, qPCR, methylation-specific PCR and pyrosequencing to analyse expression and regulation of NT5E in malignant melanoma cell lines and primary and metastatic melanomas.
Results:
NT5E is subject to epigenetic regulation in melanoma. NT5E mRNA is downregulated by methylation-dependent transcriptional silencing in the melanoma cell lines SKMel2, SKMel23, WM35, Mel501, Mel505 and C81–61 and expression is reactivated by azacytidine. In contrast, the CpG island is unmethylated and the gene expressed in cultured normal melanocytes. In clinical cases of melanoma, methylation in the NT5E CpG island occurs in both primary and metastatic melanomas and correlates with transcriptional downregulation of NT5E mRNA. Relapse with metastatic disease, particularly to the visceral sites and brain, is more common in primary melanomas lacking NT5E methylation. Primary melanomas with methylation in NT5E show limited metastatic potential or more commonly metastasise predominantly to nodal sites rather than viscera and brain (P=0.01).
Conclusion:
Deregulation of NT5E expression in melanoma occurs via epigenetic changes in the NT5E CpG island. Confirmation of our results in larger clinical series would support the candidacy of NT5E as a clinical biomarker in melanoma, which could be applied in both primary and relapsed disease. Inhibition of NT5E may have therapeutic potential in melanoma, particularly in patients with more aggressive disease metastatic to viscera or the brain.
Novel prognostic biomarkers and therapeutic strategies are urgently required for malignant melanoma. Ecto-5-prime-nucleotidase (NT5E; CD73) overexpression has been reported in several human cancers. The mechanism(s) underlying deregulated expression and the clinical consequences of changes in expression are not known.
Methods:
We used RT–PCR, qPCR, methylation-specific PCR and pyrosequencing to analyse expression and regulation of NT5E in malignant melanoma cell lines and primary and metastatic melanomas.
Results:
NT5E is subject to epigenetic regulation in melanoma. NT5E mRNA is downregulated by methylation-dependent transcriptional silencing in the melanoma cell lines SKMel2, SKMel23, WM35, Mel501, Mel505 and C81–61 and expression is reactivated by azacytidine. In contrast, the CpG island is unmethylated and the gene expressed in cultured normal melanocytes. In clinical cases of melanoma, methylation in the NT5E CpG island occurs in both primary and metastatic melanomas and correlates with transcriptional downregulation of NT5E mRNA. Relapse with metastatic disease, particularly to the visceral sites and brain, is more common in primary melanomas lacking NT5E methylation. Primary melanomas with methylation in NT5E show limited metastatic potential or more commonly metastasise predominantly to nodal sites rather than viscera and brain (P=0.01).
Conclusion:
Deregulation of NT5E expression in melanoma occurs via epigenetic changes in the NT5E CpG island. Confirmation of our results in larger clinical series would support the candidacy of NT5E as a clinical biomarker in melanoma, which could be applied in both primary and relapsed disease. Inhibition of NT5E may have therapeutic potential in melanoma, particularly in patients with more aggressive disease metastatic to viscera or the brain.
Date Issued
2012-04-10
Date Acceptance
2012-02-24
Citation
British Journal of Cancer, 2012, 106 (8), pp.1446-1452
ISSN
0007-0920
Publisher
Springer Nature [academic journals on nature.com]
Start Page
1446
End Page
1452
Journal / Book Title
British Journal of Cancer
Volume
106
Issue
8
Copyright Statement
© 2012 Cancer Research UK. This work is published under the standard license to publish agreement. After 12 months the work will become freely available and the
license terms will switch to a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License.
license terms will switch to a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000302782800012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Oncology
melanoma
NT5E
epigenetics
metastasis
ECTO-5'-NUCLEOTIDASE EN
CELL-LINES
Publication Status
Published
Date Publish Online
2012-03-27