title: Insulation of tumor suppressor genes by the nuclear factor CTCF.
abstract: One of the most outstanding nuclear factors, which has chromatin insulator and transcriptional properties and also contribute to genomic organization, is the zinc-finger protein CCCTC-binding factor (CTCF). Among its multiple functions, a growing amount of evidence implicates CTCF in the epigenetic regulation of genes responsible for the control of the cell cycle, and its mis-regulation can lead to aberrant epigenetic silencing of genes involved in cancer development. Detailed studies are now revealing that CTCF can serve as a barrier against the spread of DNA methylation and histone repressive marks over promoter regions of tumor suppressor genes. Moreover, new evidences points out to the capacity of CTCF to be covalently modified, in particular, through poly(ADP-ribosyl)ation with regulatory consequences. An unexplored aspect of CTCF is its intergenic and intragenic distribution in certain loci. Such distribution seems to facilitate the formation of an optimal chromatin structure and the recruitment of chromatin remodelers with the possible incorporation of RNA polymerase II. Therefore, in the context of tumor suppressor genes and cancer development, CTCF appears to play a relevant role by incorporating a combination of mechanisms involved in the protection against epigenetic silencing components and the maintenance of optimal higher-order organization of the corresponding loci.
authors.affiliation: Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México D.F. 04510, México. frecilla@ifc.unam.mx
authors.forename: Félix
authors.initials: F
authors.lastname: Recillas-Targa
authors.forename: Inti A
authors.initials: IA
authors.lastname: de la Rosa-Velázquez
authors.forename: Ernesto
authors.initials: E
authors.lastname: Soto-Reyes
mesh_terms: D000818:Animals; D000076246:CCCTC-Binding Factor; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D016147:Genes, Tumor Suppressor / Q000502:physiology*; D006801:Humans; D051379:Mice; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; C000619698:Ctcf protein, mouse; D012097:Repressor Proteins; D011064:Poly Adenosine Diphosphate Ribose