Biomaterial Database

Repression of class I H-2K, H-2D antigens on GR9 methylcholanthrene-induced tumour cell clones is related to the level of DNA methylation. 1986

F J Bonal, and E Pareja, and J Martin, and C Romero, and F Garrido

The correlation between gene expression and DNA methylation is well established. In the present study we examined DNA methylation as a potential regulatory mechanism of class I histocompatibility antigen expression. We selected for study two cell clones from the same mouse tumour (GR9). One of them is H-2 class I-positive (A7) and the other negative (B9). Using five enzymes and three different probes, no rearrangement or deletion was detected in the MHC class I genes of the negative clone compared with the positive one. These results do not provide an explanation for the differences observed in the expression of class I antigens in A7 (Kd, Dd positive) and B9 (Kd, Dd negative). We then studied the DNA methylation status in both clones by Southern blot analysis. Clear differences between the Kd, Dd positive and negative clones were detected. Furthermore, both Kd and Dd were clearly expressed after culturing the H-2 class I negative clone with the demethylating agent 5-azacytidine. These results suggest that the methylation of certain MHC cytosines is a regulatory mechanism of H-2 class I gene expression.

UI	MeSH Term	Description	Entries
D008745	Methylation	Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)	Methylations
D008748	Methylcholanthrene	A carcinogen that is often used in experimental cancer studies.	20-Methylcholanthrene,3-Methylcholanthrene,20 Methylcholanthrene,3 Methylcholanthrene
D009374	Neoplasms, Experimental	Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.	Experimental Neoplasms,Experimental Neoplasm,Neoplasm, Experimental
D002999	Clone Cells	A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)	Clones,Cell, Clone,Cells, Clone,Clone,Clone Cell
D004273	DNA, Neoplasm	DNA present in neoplastic tissue.	Neoplasm DNA
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D006183	H-2 Antigens	The major group of transplantation antigens in the mouse.	H2 Antigens,Antigens, H-2,Antigens, H2,H 2 Antigens
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001374	Azacitidine	A pyrimidine analogue that inhibits DNA methyltransferase, impairing DNA methylation. It is also an antimetabolite of cytidine, incorporated primarily into RNA. Azacytidine has been used as an antineoplastic agent.	Azacytidine,5-Azacytidine,NSC-102816,Vidaza,5 Azacytidine,NSC 102816,NSC102816
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus