Extensive DNA Methylation Spanning the Rb Promoter in Retinoblastoma Tumors

摘要: The retinoblastoma gene (Rb) is one of the best characterized tumor suppressor genes, and its inactivation associated with a number cancers. Previous studies have shown, by restriction enzyme analysis, that promoter region Rb methylated in significant proportion primary tumors. We now report first detailed methylation sequence analysis CpG island spanning from hypermethylated Our results show not confined to specific site, as detected studies, but extends essentially all 27 dinucleotides island, including core promoter. pattern each DNA sample different, ranging densely sparsely profiles. Single sites, particular E2F transcription factor binding well blocks CpGs, were undermethylated some samples. Possible interference could be due sequence-specific protein factors at these sites cells. This study highlights dynamics cancer cells are clearly different normal gives an insight into mechanism abnormal islands