Demethylation of repetitive DNA sequences in neuroblastoma.
Altered genomic methylcytosine content has been described for a number of tumor types, including neuroblastoma. However, it remains to be determined for different tumor types whether specific loci or chromosomal regions are affected by a methylation change or whether the change is random. We have implemented a computer-based approach for the analysis of two-dimensional separations of human genomic restriction fragments. Through the use of methylation-sensitive restriction enzymes, methylation differences in genomic DNA between tumor and normal tissues can be detected. We report the cloning and sequencing of two fragments detectable in two-dimensional separations of genomic DNA of neuroblastomas. These fragments were found to be a part of repetitive units that exhibited demethylation in neuroblastoma relative to other tumor types. Our finding of a distinct pattern of methylation of repetitive units in neuroblastoma suggests that altered methylation at certain loci may contribute to the biology of this tumor.
Thoraval
D
D
Department of Pediatrics, University of Michigan School of Medicine, Ann Arbor 48109-0510, USA.
Asakawa
J
J
Wimmer
K
K
Kuick
R
R
Lamb
B
B
Richardson
B
B
Ambros
P
P
Glover
T
T
Hanash
S
S
D001483:Base Sequence; D015139:Blotting, Southern; D019175:DNA Methylation; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA
D015252:Deoxyribonucleases, Type II Site-Specific; C038565:GCGGCCGC-specific type II deoxyribonucleases