Scientists unveil big secret of human organism

For the first time ever, researchers have mapped have mapped out the molecular "switches" that can turn on or silence individual genes in the DNA in more than 100 types of human cells, Reuters has reported.

This revolutionary achievement that unveils the complexity of genetic information is published in the expert journal Nature along with more than 20 additional papers.

Mapping is a part of a EUR 240 million worth of ten-year program funded by the US government.

The human genome is the blueprint for building an individual person. The epigenome can be thought of as the cross-outs and underlinings of that blueprint: if someone's genome contains DNA associated with cancer but that DNA is "crossed out" by molecules in the epigenome, for instance, the DNA is unlikely to lead to cancer.

As sequencing individuals' genomes to infer the risk of disease becomes more common, it will become all the more important to figure out how the epigenome is influencing that risk as well as other aspects of health.

Epigenetic differences are one reason identical twins, who have identical DNA, do not always develop the same genetic diseases, including cancer.

But incorporating the epigenome in precision medicine is daunting.

- A lifetime of environmental factors and lifestyle factors influence the epigenome, including smoking, exercising, diet, exposure to toxic chemicals and even parental nurturing - said Manolis Kellis of the Massachusets Institute of Technology, who led the mapping that involved scientists in labs from Croatia to Canada and the United States.

Not only will scientists have to decipher how the epigenome affects genes, they will also have to determine how the lives people lead affect their epigenome.

The human genome is the sequence of all the DNA on chromosomes. The DNA is identical in every cell - from neurons to hearts to skin, and it falls to the epigenome to differentiate the cells.

The epigenome map shows how each of 127 tissue and cell types differs from every other at the level of DNA.

One of the resulting studies show, for instance, that brain cells from people who died with Alzheimer's disease had epigenetic changes in DNA involved in immune response.

Alzheimer's has never been seen as an immune-system disorder, so the discovery opens up another possible avenue to understand and treat it.

Epigenetic information might offer a life-saving clue for oncologists trying to determine treatment, said co-senior author Shamil Sunyaev, a research geneticist at Brigham and Women's Hospital in Boston.

- I very much see this as the beginning of a decade of epigenomics - says Kellis.