p19-INK4d inhibits neuroblastoma cell growth, induces differentiation and is hypermethylated and downregulated in MYCN-amplified neuroblastomas.

Abstract

Uncontrolled cell cycle entry, resulting from deregulated CDK-RB1-E2F pathway activity, is a crucial determinant of neuroblastoma cell malignancy. Here we identify neuroblastoma-suppressive functions of the p19-INK4d CDK inhibitor and uncover mechanisms of its repression in high-risk neuroblastomas. Reduced p19-INK4d expression was associated with poor event-free and overall survival and neuroblastoma risk factors including amplified MYCN in a set of 478 primary neuroblastomas. High MYCN expression repressed p19-INK4d mRNA and protein levels in different neuroblastoma cell models with conditional MYCN expression. MassARRAY and 450K methylation analyses of 105 primary neuroblastomas uncovered a differentially methylated region within p19-INK4d. Hypermethylation of this region was associated with reduced p19-INK4d expression. In accordance, p19-INK4d expression was activated upon treatment with the demethylating agent, 2'-deoxy-5-azacytidine, in neuroblastoma cell lines. Ectopic p19-INK4d expression decreased viability, clonogenicity and the capacity for anchorage-independent growth of neuroblastoma cells, and shifted the cell cycle towards the G1/0 phase. p19-INK4d also induced neurite-like processes and markers of neuronal differentiation. Moreover, neuroblastoma cell differentiation, induced by all-trans retinoic acid or NGF-NTRK1-signaling, activated p19-INK4d expression. Our findings pinpoint p19-INK4d as a neuroblastoma suppressor and provide evidence for MYCN-mediated repression and for epigenetic silencing of p19-INK4d by DNA hypermethylation in high-risk neuroblastomas.

• Authors: Daniel Dreidax, Steffen Bannert, Kai-Oliver Henrich, Christina Schröder, Sebastian Bender, Christopher C Oakes, Sven Lindner, Johannes H Schulte, David Duffy, Thomas Schwarzl, Maral Saadati, Volker Ehemann, Axel Benner, Stefan Pfister, Matthias Fischer, Frank Westermann
• Journal: Human molecular genetics (Hum Mol Genet) Vol. 23 Issue 25 Pg. 6826-37 (Dec 20 2014) ISSN: 1460-2083 [Electronic] England
• PMID: 25104850 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected].

Chemical References

• Antimetabolites, Antineoplastic
• CDKN2D protein, human
• Cyclin-Dependent Kinase Inhibitor p19
• MYCN protein, human
• N-Myc Proto-Oncogene Protein
• Nuclear Proteins
• Oncogene Proteins
• Tretinoin
• Decitabine
• Azacitidine

Topics

• Adolescent
• Adult
• Antimetabolites, Antineoplastic (pharmacology)
• Azacitidine (analogs & derivatives, pharmacology)
• Cell Differentiation (drug effects)
• Cell Line, Tumor
• Child
• Child, Preschool
• Cyclin-Dependent Kinase Inhibitor p19 (genetics, metabolism)
• DNA Methylation (drug effects)
• Decitabine
• Epigenesis, Genetic
• Female
• Gene Expression Regulation, Neoplastic
• Humans
• Infant
• Infant, Newborn
• Male
• N-Myc Proto-Oncogene Protein
• Neoplasm Staging
• Nervous System Neoplasms (genetics, metabolism, mortality, pathology)
• Neuroblastoma (genetics, metabolism, mortality, pathology)
• Neurons (drug effects, metabolism, pathology)
• Nuclear Proteins (genetics, metabolism)
• Oncogene Proteins (genetics, metabolism)
• Signal Transduction
• Survival Analysis
• Tretinoin (pharmacology)