Linked Life Data

17043645

Source:http://linkedlifedata.com/resource/pubmed/id/17043645

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2007-4-12
pubmed:abstractText
In human post-natal somatic cells, low global levels of DNA methylation have been associated with the hypomethylation of several repetitive elements, a feature that has been proposed to be a surrogate epigenetic marker. These data, mainly derived from the analysis of cancer cells, suggest a potential association between loss of cell-growth control and altered differentiation with hypomethylation of repetitive sequences. Partial hydatidiform moles (PHMs) can be used as an alternative model for investigating this association in a non-tumorigenic context. This gestational disease is characterized by abnormal overgrowth and differentiation of the placenta and spontaneous abortion. Here, we comprehensively analyse the DNA methylation of these trophoblastic tissues in both PHM and normal placenta at global and sequence-specific levels. Analysis of the global 5-methylcytosine content and immunohistochemistry indicate that PHM and normal placenta have identical global levels of DNA methylation. In contrast, bisulfite genomic sequencing shows that, whereas Alu, NBL2 and satellite 2 repetitive elements are equally methylated, LINE-1 sequences are hypermethylated in PHM tissues ( approximately 2-fold relative to normal placenta). Interestingly, altered demethylation is also found in triploid diandric embryos that originate from dispermic fertilization of an oocyte, a common event responsible for most PHMs. In conclusion, alterations of DNA methylation do not seem to be randomly distributed in PHM, as several repeated elements remain unaltered, whereas LINE-1 sequences are hypermethylated. In addition, our findings suggest that the hypomethylation of repetitive elements in cancer is directly linked to the neoplasic process and not a simple consequence of loss of growth control observed in most of the cancer cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2518-24
pubmed:dateRevised
2007-7-12
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Specific hypermethylation of LINE-1 elements during abnormal overgrowth and differentiation of human placenta.
pubmed:affiliation
Unité INSERM 590, Laboratoire d'Oncologie Moléculaire, Centre Léon Bérard, Lyon Cedex, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't