Related Experiment Video
Updated: Jun 25, 2026
Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
Published on: February 21, 2015
Detection of CpG island hypermethylation of caspase-8 in neuroblastoma using an oligonucleotide array
Arata Kamimatsuse1, Kaoru Matsuura, Shogo Moriya
1Department of Surgery, Graduate School of Biomedical Science, Hiroshima University, Hiroshima, Japan.
Background:
The caspase-8 gene (CASP8) is frequently inactivated in unfavorable neuroblastomas through DNA methylation. The present study utilized oligoarrays to evaluate the methylation status of a CpG island located between exons 2 and 3 of caspase 8 in neuroblastomas.
Procedure:
DNA derived from 70 neuroblastomas was amplified by PCR after bisulfate modification and subjected to analysis on a self-made oligoarray that utilized a polycarbodiimide-coated slide to detect methylation of six intragenic CpG islands of caspase 8. In 30 cases, the methylation status was also analyzed by sequencing. In six cases, the PCR product was cloned into a vector and analyzed.
Results:
Among the 70 tumor-derived DNAs, methylation was not detected in 18 cases, one methylated CpG was found in 12 cases, two in 18 cases, three in 3 cases, four in 8 cases, five in 1 case and six in 10 cases. All methylated CpG loci detected by sequencing were detected by oligoarray, but some methylated CpGs in three loci were detected by oligoarray alone. In these discrepant loci, methylation was detected in some clones after subcloning, indicating that the oligoarray might be more sensitive than sequencing. The CASP8 expression level was depressed in the tumors having two distinct CpG doublets. These results were significantly correlated with MYCN amplification and with clinical outcomes.
Conclusions:
A significant difference in the methylation status within the CpG island of CASP8 was shown between favorable and unfavorable subtypes, and CASP8 methylation detected by oligoarray may be useful in the clinical evaluation of neuroblastomas.
Insights
DNA methylation of the caspase-8 gene (CASP8) is linked to unfavorable neuroblastomas. Oligoarray analysis revealed CASP8 methylation patterns correlate with clinical outcomes, aiding in neuroblastoma evaluation.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Caspase-8 gene (CASP8) inactivation via DNA methylation is common in unfavorable neuroblastomas.
- Investigating the methylation status of a specific CpG island in CASP8 is crucial for understanding neuroblastoma progression.
Purpose of the Study:
- To evaluate the methylation status of a CpG island within the caspase-8 gene (CASP8) in neuroblastomas using oligoarrays.
- To correlate CASP8 methylation patterns with clinical outcomes and MYCN amplification in neuroblastoma patients.
Main Methods:
- DNA from 70 neuroblastomas was analyzed for CASP8 CpG island methylation using bisulfite modification, PCR, and a custom oligoarray.
- Methylation status was cross-validated with sequencing and subcloning in select cases.
- Oligoarray sensitivity was compared to traditional sequencing methods.
Main Results:
- CASP8 methylation was detected across varying CpG loci in 52 out of 70 neuroblastomas.
- Oligoarray analysis demonstrated potentially higher sensitivity than sequencing for detecting certain methylated CpGs.
- Reduced CASP8 expression correlated with specific methylation patterns and was linked to MYCN amplification and poorer clinical outcomes.
Conclusions:
- Significant differences in CASP8 CpG island methylation exist between favorable and unfavorable neuroblastoma subtypes.
- Oligoarray-based detection of CASP8 methylation shows promise as a clinical tool for neuroblastoma evaluation.
