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Updated: May 14, 2026
Neurogenesis Using P19 Embryonal Carcinoma Cells
Published on: April 27, 2019
Low p14ARF expression in neuroblastoma cells is associated with repressed histone mark status, and enforced
Daniel Dreidax1, Sina Gogolin, Christina Schroeder
1Division of Tumor Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Abstract:
The TP53 tumor suppressor pathway is abrogated by TP53 mutations in the majority of human cancers. Increased levels of wild-type TP53 in aggressive neuroblastomas appear paradox but are tolerated by tumor cells due to co-activation of the TP53 ubiquitin ligase, MDM2. The role of the MDM2 antagonist, p14(ARF), in controlling the TP53-MDM2 balance in neuroblastoma is unresolved. In the present study, we show that conditional p14(ARF) expression substantially suppresses viability, clonogenicity and anchorage-independent growth in p14(ARF)-deficient or MYCN-amplified neuroblastoma cell lines. Furthermore, ectopic 14(ARF) expression induced accumulation of cells in the G1 phase and apoptosis, which was paralleled by accumulation of TP53 and its targets. Comparative genomic hybridization analysis of 193 primary neuroblastomas detected one homozygous deletion of CDKN2A (encoding both p14(ARF) and p16(INK4A)) and heterozygous loss of CDKN2A in 22% of tumors. Co-expression analysis of p14(ARF) and its transactivator, E2F1, in a set of 68 primary tumors revealed only a weak correlation, suggesting that further regulatory mechanisms govern p14(ARF) expression in neuroblastomas. Intriguingly, analyses utilizing chromatin immunoprecipitation revealed different histone mark-defined epigenetic activity states of p14(ARF) in neuroblastoma cell lines that correlated with endogenous p14(ARF) expression but not with episomal p14(ARF) promoter reporter activity, indicating that the native chromatin context serves to epigenetically repress p14(ARF) in neuroblastoma cells. Collectively, the data pinpoint p14(ARF) as a critical factor for efficient TP53 response in neuroblastoma cells and assign p14(ARF) as a neuroblastoma suppressor candidate that is impaired by genomic loss and epigenetic repression.
Insights
The tumor suppressor p14(ARF) inhibits neuroblastoma growth by stabilizing TP53. Genomic loss and epigenetic repression impair p14(ARF) function, highlighting its role in neuroblastoma suppression.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- The TP53 tumor suppressor pathway is often compromised in cancer by TP53 mutations.
- In neuroblastoma, wild-type TP53 levels increase but are tolerated due to MDM2 co-activation.
- The role of p14(ARF), an MDM2 antagonist, in regulating the TP53-MDM2 balance in neuroblastoma remains unclear.
Purpose of the Study:
- To investigate the function of p14(ARF) in neuroblastoma.
- To determine the mechanisms regulating p14(ARF) expression and activity in neuroblastoma cells.
Main Methods:
- Conditional p14(ARF) expression in neuroblastoma cell lines.
- Cell viability, clonogenicity, and cell cycle assays.
- Comparative genomic hybridization (CGH) and chromatin immunoprecipitation (ChIP).
Main Results:
- Conditional p14(ARF) expression suppressed neuroblastoma cell viability, clonogenicity, and anchorage-independent growth.
- Ectopic p14(ARF) induced G1 arrest, apoptosis, and accumulation of TP53 and its targets.
- CDKN2A (encoding p14(ARF)) deletions were found in 22% of primary neuroblastomas.
- Epigenetic repression of p14(ARF) was observed in neuroblastoma cell lines, independent of promoter reporter activity.
Conclusions:
- p14(ARF) is a critical factor for effective TP53 response in neuroblastoma.
- p14(ARF) acts as a neuroblastoma suppressor, with its function impaired by genomic loss and epigenetic repression.
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