title: DNA methylation in states of cell physiology and pathology.
abstract: DNA methylation is one of epigenetic mechanisms regulating gene expression. The methylation pattern is determined during embryogenesis and passed over to differentiating cells and tissues. In a normal cell, a significant degree of methylation is characteristic for extragenic DNA (cytosine within the CG dinucleotide) while CpG islands located in gene promoters are unmethylated, except for inactive genes of the X chromosome and the genes subjected to genomic imprinting. The changes in the methylation pattern, which may appear as the organism age and in early stages of cancerogenesis, may lead to the silencing of over ninety endogenic genes. It has been found, that these disorders consist not only of the methylation of CpG islands, which are normally unmethylated, but also of the methylation of other dinucleotides, e.g. CpA. Such methylation has been observed in non-small cell lung cancer, in three regions of the exon 5 of the p53 gene (so-called "non-CpG" methylation). The knowledge of a normal methylation process and its aberrations appeared to be useful while searching for new markers enabling an early detection of cancer. With the application of the Real-Time PCR technique (using primers for methylated and unmethylated sequences) five new genes which are potential biomarkers of lung cancer have been presented.
authors.affiliation: Department of Thoracic Surgery, Medical University of Bialystok, Poland. anettasul@poczta.onet.pl
authors.forename: Anetta
authors.initials: A
authors.lastname: Sulewska
authors.forename: Wieslawa
authors.initials: W
authors.lastname: Niklinska
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Kozlowski
authors.forename: Lukasz
authors.initials: L
authors.lastname: Minarowski
authors.forename: Wojciech
authors.initials: W
authors.lastname: Naumnik
authors.forename: Jacek
authors.initials: J
authors.lastname: Niklinski
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dabrowska
authors.forename: Lech
authors.initials: L
authors.lastname: Chyczewski
mesh_terms: D000818:Animals; D043171:Chromosomal Instability; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000502:physiology; D005057:Eukaryotic Cells / Q000502:physiology*; D020868:Gene Silencing; D006801:Humans; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism
chemical_list: D015254:DNA Modification Methylases