Mapping the first gene of 5hmC molecule in human embryonic stem cells

Stem cell researchers at UCLA, USA, have completed the first genome map of a DNA modification called 5-hydroxymethylcytosine (5hmC) in human embryonic stem cells, and found that It is mainly found in genes that are turned on, or active.

The findings of researchers working at the Eli and Edythe Broad Research Center for Stem Cells and Regenerative Medicine, UCLA University, USA, may help prove the important role of some regulatory genes. , in controlling disease development of diseases such as cancer.

Professor Steven E Jacobsen

" Any way, gene control is very important in the treatment of human disease, including cancer ," said Steven E Jacobsen, a professor of molecular, cell and biological science, specializing in the study of Organism's development in the Division of Life Sciences and as an investigator of the Hughes Medical Institute. " Cancer is generally a problem of genes that are not turned off properly or mutations, such as tumor-killing genes, or genes that should stay off are turned on ."

The results of the study were published in Genome Biology .

The 5hmC molecule is formed from the cytosine base in DNA by adding a methyl group and then a hydroxy group . The molecule is very important in epigenetics - studies of changes in gene expression due to other mechanisms that are not changed in the DNA sequence caused by the hydroxymethyl group newly formed on cytosine capable of transferring a gene and off, Jacobsen said.

Recently discovered 5hmC molecule, and its function is not well understood. So far, researchers still do not know how 5hmC's layout is in the genome.

Jacobsen, a researcher at Jonsson Cancer Research Center, UCLA University, USA, said: " Understanding the mechanism of 5hmC molecules is important. We already know that DNA can be modified by 5hmC, but unknown, where on the genome occurs . "

Jacobsen conducted genetic molecular laboratory research and studied the genetic structure of the DNA methylation pattern using a genetic structural study to determine the presence of 5hmC in human embryonic stem cells. They used human embryonic stem cells because it showed that 5hmC molecules were previously abundant in those cells as well as in brain cells.

In the study, according to Jacobsen, 5hmC is involved in genes and tends to be found on active genes. The study also revealed that 5hmC was present on a type of DNA regulatory factor, called an adjunct, to help control gene expression. In particular, 5hmC is already present on auxiliaries that are important to determine the nature of human embryonic stem cells.

Results showed that 5hmC plays an important role in activating genes . This is in contrast to the role of 5mC in the study (DNA methylation), which is involved in inhibiting gene activity. This relationship is consistent with the view that 5hmC is generated directly from 5mC.

" If we can understand the 5hmC function, we will better understand how genes are turned on and off, and can help develop methods to control regulatory dominant genes ," Jacobsen said.

In the future, Jacobsen and his team will seek to explore the mechanisms by which 5hmC is made of DNA methylation and how it locates specific areas of the genome, in the role of support substances.

The study was funded by the Howard Hughes Medical Institute, Practical Doctorate Fellowship Fred Eiserling and Judith Lengyel, Association of Leukemia & Lymphoma, National Institutes of Health and creative award from the Center for Regenerative Medicine & Eli Broad and Edythe stem cell research, UCLA University, USA.