Association of epigenetic inactivation of RASSF1A with poor outcome in human neuroblastoma.
OBJECTIVE
To investigate the prevalence and potential clinical significance of epigenetic aberrations in neuroblastoma (NB).


METHODS
The methylation status of 11 genes that are frequently epigenetically inactivated in adult cancers was assayed in 13 NB cell lines. The prevalence of RASSF1A and TSP-1 methylation was also analyzed in 56 NBs and 5 ganglioneuromas by methylation-specific PCR. Associations between the methylation status of RASSF1A and TSP-1 and patient age, tumor stage, tumor MYCN status, and patient survival were evaluated.


RESULTS
Epigenetic changes were detected in all 13 NB cell lines, although the pattern of gene methylation varied. The putative tumor suppressor gene RASSF1A was methylated in all 13 cell lines, and TSP-1 and CASP8 were methylated in 11 of 13 cell lines. Epigenetic changes of DAPK and FAS were detected in only small numbers of cell lines, whereas none of the cell lines had methylation of p16, p21, p73, RAR-beta2, SPARC, or TIMP-3. RASSF1A was also methylated in 70% of the primary NB tumors tested, and TSP-1 methylation was detected in 55% of the tumors. RASSF1A methylation was significantly associated with age >1 year (P < 0.01), high-risk disease (P < 0.016), and poor survival (P < 0.001). In contrast, no association between TSP-1 methylation and prognostic factors or survival was observed.


CONCLUSIONS
Our results suggest that epigenetic inactivation of RASSF1A may contribute to the clinically aggressive phenotype of high-risk NB.
Yang
Qiwei
Q
The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
Zage
Peter
P
Kagan
David
D
Tian
Yufeng
Y
Seshadri
Roopa
R
Salwen
Helen R
HR
Liu
Shuqing
S
Chlenski
Alexandre
A
Cohn
Susan L
SL
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D044127:Epigenesis, Genetic; D005260:Female; D005729:Ganglioneuroma / Q000235:genetics / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D016147:Genes, Tumor Suppressor; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D007223:Infant; D008297:Male; D009363:Neoplasm Proteins / Q000235:genetics*; D009447:Neuroblastoma / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D015996:Survival Rate; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000235:genetics*
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; C411762:RASSF1 protein, human; C481348:SPZ1 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins