Abstract
The retinoblastoma susceptibility (RB1) gene contains an unmethylated CpG-rich island at its 5' end. Using methylation-sensitive restriction enzymes, we have investigated the methylation status of this island in 21 sporadic unilateral retinoblastomas and 30 hereditary retinoblastomas. Three sporadic unilateral tumors were found to have hypermethylated RB1 alleles. In two tumors, the paternal allele was methylated, whereas the maternal allele had been lost. Cultured cells from one of these tumors were studied by the reverse transcription polymerase chain reaction and found to have a reduced level of RB1 mRNA. The third tumor had retained constitutional heterozygosity, and the paternal allele was specifically methylated. The combined data from previously published reports and from this study show that hypermethylation of the RB1 gene occurs in 13% of sporadic unilateral tumors and may reduce gene activity.
MeSH Terms
Base Sequence
DNA, Neoplasm/analysis,blood,metabolism
Dinucleoside Phosphates/genetics,metabolism
Eye Neoplasms/genetics,metabolism
Gene Frequency
Genes, Retinoblastoma/genetics
Humans
Methylation
Molecular Sequence Data
Polymerase Chain Reaction
Retinoblastoma/genetics,metabolism
Sequence Analysis, DNA
Sex Factors
Tumor Cells, Cultured
Chemicals
DNA, Neoplasm
Dinucleoside Phosphates
cytidylyl-3'-5'-guanosine
Authors & Affiliations
6 authors, click to expand affiliations / ORCID
Greger V
Institut für Humangenetik, Universitätsklinikum Essen, Germany.
Debus N
Lohmann D
Höpping W
Passarge E
Horsthemke B
References (18)
18 references, click to expand
-
Detection of small RB1 gene deletions in retinoblastoma by multiplex PCR and high-resolution gel electrophoresis.
Hum Genet. 1992 Apr;89(1):49-53
PMID: 1577465
-
Analysis of human Y-chromosome-specific reiterated DNA in chromosome variants.
Proc Natl Acad Sci U S A. 1977 Mar;74(3):1245-9
PMID: 265567
-
Genetics and cytogenetics of retinoblastoma.
Cancer Genet Cytogenet. 1992 Oct 1;63(1):1-7
PMID: 1423220
-
The inheritance of epigenetic defects.
Science. 1987 Oct 9;238(4824):163-70
PMID: 3310230
-
Newly established human retinoblastoma cell lines exhibit an "immortalized" but not an invasive phenotype in vitro.
Int J Cancer. 1990 Jul 15;46(1):125-32
PMID: 2365495
-
No evidence for sequences structurally related to the RB1 gene in the human genome.
Hum Genet. 1991 Feb;86(4):401-3
PMID: 1999343
-
Interclonal variation in methylation patterns for expressed and non-expressed genes.
Nucleic Acids Res. 1982 Jul 24;10(14):4293-304
PMID: 6896910
-
Characterization of deletions at the retinoblastoma locus in patients with bilateral retinoblastoma.
Am J Med Genet. 1991 May 1;39(2):196-200
PMID: 2063924
-
CpG methylation inactivates the promoter activity of the human retinoblastoma tumor-suppressor gene.
Oncogene. 1993 Apr;8(4):1063-7
PMID: 8455933
-
Epigenetic changes may contribute to the formation and spontaneous regression of retinoblastoma.
Hum Genet. 1989 Sep;83(2):155-8
PMID: 2550354
-
Prediction of the risk of hereditary retinoblastoma, using DNA polymorphisms within the retinoblastoma gene.
N Engl J Med. 1988 Jan 21;318(3):151-7
PMID: 2892131
-
Human retinoblastoma susceptibility gene: genomic organization and analysis of heterozygous intragenic deletion mutants.
Proc Natl Acad Sci U S A. 1988 Apr;85(7):2210-4
PMID: 2895471
-
Complete genomic sequence of the human retinoblastoma susceptibility gene.
Genomics. 1993 Sep;17(3):535-43
PMID: 7902321
-
DNA methylation and gene activity.
Cell. 1988 Apr 8;53(1):3-4
PMID: 3280142
-
Point mutation analysis in a mammalian gene: rapid preparation of total RNA, PCR amplification of cDNA, and Taq sequencing by a novel method.
Biotechniques. 1989 May;7(5):494-6, 498-9
PMID: 2483818
-
Allele-specific hypermethylation of the retinoblastoma tumor-suppressor gene.
Am J Hum Genet. 1991 May;48(5):880-8
PMID: 1673287
-
Application of linkage analysis to genetic counselling in families with hereditary retinoblastoma.
J Med Genet. 1988 Apr;25(4):217-21
PMID: 3163379
-
Structure and partial genomic sequence of the human retinoblastoma susceptibility gene.
Gene. 1989 Aug 1;80(1):119-28
PMID: 2701949