DNA methylation patterns are significantly reorganized during carcinogenesis, which is accompanied by altered gene expression, reduced plasticity of the transcriptional landscape, possible reactivation of transposable elements, and chromosomal instability.
One was the acquisition or reactivation of mobile elements in the chromosomes of wild flies.
While the contribution of genome hypomethylation in cancer development and progression is explained by several mechanisms: chromosomal instability, loss of imprinting, and reactivation of transposable elements [3], [4], the molecular causes of genome hypomethylation remain unclear.
Third, reactivation of transposable elements (TEs) following polyploidization in synthetic hexaploid wheats (Triticum) was considered to participate in regulation of the transcription of neighbouring genes [ 72].
Global DNA hypomethylation generally occurs in centromeric repeats and repetitive sequences and contributes to carcinogenesis by causing chromosomal instability, reactivation of transposable elements, and loss of imprinting [ 25].
Reactivation of transposable elements during stress conditions have been found in many organisms from fission yeast to plants and animals (reviewed in [ 65]).
DNA hypomethylation contributes to cancer development through an increase in genomic instability, reactivation of transposable elements, and loss of imprinting (Esteller 2002).
Genomic DNA hypomethylation is believed to have an important impact on tumor biology through the generation of chromosomal instability, reactivation of transposable elements, and loss of imprinting [ 27].
Global hypomethylation events are enriched for repetitive sequences and thought to be responsible for the reactivation of retrotransposon elements during age, as one mechanism leading to a higher incidence of cancer.
This phenomena is also not well understood, but may contribute to carcinogenesis by several mechanisms, such as loss of imprinting, chromosomal instability, and reactivation of transposable elements (reviewed in Esteller, 2003).
