Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Human embryonic stem cells display a unique pattern of chemical modification to DNA

08.08.2006
Study suggests additional hurdles to therapeutic cloning may lie ahead

Scientists from the Burnham Institute for Medical Research (BIMR) and Illumina Inc., in collaboration with stem cell researchers around the world, have found that the DNA of human embryonic stem cells is chemically modified in a characteristic, predictable pattern. This pattern distinguishes human embryonic stem cells from normal adult cells and cell lines, including cancer cells. The study, which appears online today in Genome Research, should help researchers understand how epigenetic factors contribute to self-renewal and developmental pluripotence, unique characteristics of human embryonic stem cells that may one day allow them to be used to replace diseased or damaged cells with healthy ones in a process called therapeutic cloning.

Embryonic stem cells are derived from embryos that are undergoing a period of intense cellular activity, including the chemical addition of methyl groups to specific DNA sequences in a process known as DNA methylation. The methylation and demethylation of particular DNA sequences in the genome are known to have profound effects on cellular behavior and differentiation. For example, DNA methylation is one of the critical epigenetic events leading to the inactivation of one X chromosome in female cells. Failure to establish a normal pattern of DNA methylation during embryogenesis can cause immunological deficiencies, mental retardation and other abnormalities such as Rett, Prader-Willi, Angelman and Beckwith-Wiedemann syndromes.

Until recently, DNA methylation could only be studied one gene at a time. But a new microarray-based technique developed at Illumina enabled the scientists conducting this new study to simultaneously examine hundreds of potential methylation sites, thereby revealing global patterns. "Analyzing the DNA methylation pattern of hundreds of genes at a time opens a new window for epigenetic research," says Dr. Jian-Bing Fan, director of molecular biology at Illumina. "Exciting insights into development, aging, and cancer should come quickly from understanding global patterns of DNA methylation."

To examine global DNA methylation patterns in human embryonic stem cells, the researchers analyzed 14 human embryonic stem cell lines from diverse ethnic origins, derived in several different labs, and maintained for various times in culture. They tested over 1500 potential methylation sites in the DNA of these cells and in other cell types and found that the embryonic stem cells shared essentially identical methylation patterns in a large number of gene regions. Furthermore, these methylation patterns were distinct from those in adult stem cells, differentiated cells, and cancer cells.

"Our results suggest that therapeutic cloning of patient-specific human embryonic stem cells will be an enormous challenge, as nuclei from adult cells will have to be epigenetically reprogrammed to reflect the specific DNA methylation signature of normal human embryonic stem cells," explains Dr. Jeanne Loring, co-director of the stem cell center at BIMR. "This reinforces the need for basic research directed at understanding the fundamental biology of human embryonic stem cells before therapeutic uses can be considered."

Maria Smit | EurekAlert!
Further information:
http://www.cshl.edu
http://www.genome.org

More articles from Life Sciences:

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke

29.05.2017 | Life Sciences

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>