DNA methylation and expression patterns of key tissue-specific genes in adult stem cells and stomach tissues.
CpG-island margins and non-island-CpG sites round the transcription start sites of CpG-island-positive and -negative genes are methylated to various degrees in a tissue-specific manner. These methylation-variable CpG sites were analyzed to delineate a relationship between the methylation and transcription of the tissue-specific genes. The level of tissue-specific transcription was estimated by counting the number of the total transcripts in the SAGE (serial analysis of gene expression) database. The methylation status of 12 CpG-island margins and 21 non-island CpG sites near the key tissue-specific genes was examined in pluripotent stromal cells obtained from fat and bone marrow samples as well as in lineage-committed cells from marrow bulk, stomach, colon, breast, and thyroid samples. Of the 33 CpG sites examined, 10 non-island-CpG sites, but none of the CpG-island margins were undermethylated concurrent with tissue-specific expression of their nearby genes. The net methylation of the 33 CpG sites and the net amount of non-island-CpG gene transcripts were high in stomach tissues and low in stromal cells. The present findings suggest that the methylation of the non-island-CpG sites is inversely associated with the expression of the nearby genes, and the concert effect of transitional-CpG methylation is linearly associated with the stomach-specific genes lacking CpG-islands.
Hong
Seung-Jin
SJ
Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Kang
Moo-Il
MI
Oh
Jung-Hwan
JH
Jung
Yu-Chae
YC
Kim
Young-Ho
YH
Kim
Sung-Ja
SJ
Choi
Seung-Hye
SH
Seo
Eun-Joo
EJ
Choi
Sang-Wook
SW
Rhyu
Mun-Gan
MG
D000273:Adipose Tissue / Q000166:cytology; D000293:Adolescent; D000328:Adult; D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism*; D000368:Aged; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D013270:Stomach / Q000166:cytology; D017154:Stromal Cells / Q000378:metabolism; D024363:Transcription Initiation Site; D014158:Transcription, Genetic