Embryonic Stem Cell (ES)-Specific Enhancers Specify the Expression Potential of ES Genes in Cancer.

Cancers often display gene expression profiles resembling those of undifferentiated cells. The mechanisms controlling these expression programs have yet to be identified. Exploring transcriptional enhancers throughout hematopoietic cell development and derived cancers, we uncovered a novel class of regulatory epigenetic mutations.

Premature aging of leukocyte DNA methylation is associated with type 2 diabetes prevalence.

Background: Type 2 diabetes mellitus (T2D) is highly prevalent in Middle-Eastern and North African Arab populations, but the molecular basis for this susceptibility is unknown. Altered DNA methylation levels were reported in insulin-secreting and responding tissues, but whether methylation in accessible tissues such as peripheral blood is associated with T2D risk remains an open question. Age-related alteration of DNA methylation level was reported in certain methylation sites, but no association with T2D has been shown.

Reactivation of epigenetically silenced miR-512 and miR-373 sensitizes lung cancer cells to cisplatin and restricts tumor growth.

MicroRNAs (miRs) regulate a variety of cellular processes, and their impaired expression is involved in cancer. Silencing of tumor-suppressive miRs in cancer can occur through epigenetic modifications, including DNA methylation and histone deacetylation. We performed comparative miR profiling on cultured lung cancer cells before and after treatment with 5'aza-deoxycytidine plus Trichostatin A to reverse DNA methylation and histone deacetylation, respectively.

Genome-wide survey reveals predisposing diabetes type 2-related DNA methylation variations in human peripheral blood.

Inter-individual DNA methylation variations were frequently hypothesized to alter individual susceptibility to Type 2 Diabetes Mellitus (T2DM). Sequence-influenced methylations were described in T2DM-associated genomic regions, but evidence for direct, sequence-independent association with disease risk is missing. Here, we explore disease-contributing DNA methylation through a stepwise study design: first, a pool-based, genome-scale screen among 1169 case and control individuals revealed an excess of differentially methylated sites in genomic regions that were previously associated with T2DM through genetic studies.

Replication timing-related and gene body-specific methylation of active human genes.

Understanding how the epigenetic blueprint of the genome shapes human phenotypes requires systematic evaluation of the complex interplay between gene activity and the different layers of the epigenome. Utilizing microarray-based techniques, we explored the relationships between DNA methylation, DNA replication timing and gene expression levels across a variety of human tissues and cell lines. The analyses revealed unequal methylation levels among early- and late-replicating fractions of the genome: late-replicating DNA was hypomethylated compared with early-replicating DNA.