DNA methylation and differentiation of human keratinocytes.
DNA methylation is a postreplicative modification thought to play a role in gene transcription in eucaryotes. Differences in the amount of 5-methylcytosine as a function of age and differentiation state have been reported. DNA isolated from human skin keratinocytes was analyzed for its 5-methylcytosine content. The 5-methylcytosine in DNA from neonatal and adult human keratinocytes was found to vary as a function of differentiation state. Differentiation of keratinocytes in vitro was promoted using a simple method where keratinocytes were plated directly onto the plastic surface of a culture flask, grown to confluence, and placed on a rocking culture platform that cyclically exposed the cells to air 50% of the time. Terminal differentiation was evident after approximately three weeks in culture. The 5-methylcytosine content of the DNA from differentiated human keratinocytes was 1.4%, whereas that of undifferentiated human keratinocytes was 3.1%. No difference in the 5-methylcytosine content of DNA as a function of the age of the donor was found.
Veres
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DA
Department of Physiology, Gillette Research Institute, Gaithersburg, Maryland 20879.
Wilkins
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Coble
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Lyon
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SB
D044503:5-Methylcytosine; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism; D007633:Keratins / Q000378:metabolism; D008745:Methylation; D008854:Microscopy, Electron; D008970:Molecular Weight
D007633:Keratins; D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA