In cancer, an embryonic gene-silencing mechanism gone awry

October 4, 2012 in Genetics

There are some genes that are only activated in the very first days of an embryo's existence. Once they have accomplished their task, they are shut down forever, unlike most of our genes, which remain active throughout our lives. EPFL scientists have unveiled part of this strange mechanism. The same process, accidentally initiated later in life, could be responsible for many kinds of cancer. The discovery is described in a recent article in the journal Cell Reports.

The researchers identified a group of proteins that play a key role in this phenomenon. They bind to a DNA sequence near the gene, and substitute one DNA element for another, essentially "marking" the sequence. This phenomenon is known as "methylation." Once the marker is in place, the recognizes the sign and maintains the gene in a dormant state.

"It's an extremely elegant mechanism. The genes are needed right at the beginning of embryonic development, but rather than deactivate them every time a cell divides, the job is done in one fell swoop, once the genes are no longer required," explains EPFL professor Didier Trono, who co-authored the article. "This process is also involved in the control of , which make up almost half of our genome, and must be inactivated very early in development."

This gene-silencing mechanism, which normally takes place in a several-day-old embryo, can also occur accidentally later in life. In many , certain genes have been marked by methylation; they have been silenced. If, for example, the gene responsible for controlling cell division has been methylated, the consequences are all too easy to imagine. "The embryonic process, which is designed to silence certain genes, can be fortuitously reactivated, leading to the formation of ."

It is still not understood why the process stops after the first days of , even though many of the active proteins continue to be expressed in the cell, says Trono. "If we can figure out how this cellular clock works, then we would perhaps be able to understand how the mechanism is reactivated later, leading to the development of cancer."

Journal reference: Cell Reports search and more info website

Provided by Ecole Polytechnique Federale de Lausanne search and more info website

not rated yet  

Rank not rated yet
Relevant PhysicsForums posts

More news stories

Researchers develop model for better testing, targeting of malignant peripheral nerve sheath tumors

University of Minnesota Medical School researchers from the Masonic Cancer Center, University of Minnesota, in partnership with the University's Brain Tumor Program, have developed a new mouse model of malignant peripheral ...

Genetics created May 20, 2013 | popularity 5 / 5 (1) | comments 0 | with audio podcast

Researchers identify new circadian clock component

Northwestern University scientists have shown a gene involved in neurodegenerative disease also plays a critical role in the proper function of the circadian clock.

Genetics created May 16, 2013 | popularity 3 / 5 (1) | comments 1 | with audio podcast

Returning genetic incidental findings without patient consent violates basic rights, experts say

Informed consent is the backbone of patient care. Genetic testing has long required patient consent and patients have had a "right not to know" the results. However, as 21st century medicine now begins to use the tools of ...

Genetics created May 16, 2013 | popularity 5 / 5 (1) | comments 3 | with audio podcast

Ethicists provide framework supporting new recommendations on reporting incidental findings in gene sequencing

In a paper published in Science Express, a group of experts led by bioethicists in the Center for Medical Ethics and Health Policy at Baylor College of Medicine provide a framework for the new American College of Medical Geneti ...

Genetics created May 16, 2013 | popularity not rated yet | comments 0

Experts urge caution over use of new genetic sequencing techniques

The use of genome-wide analysis (GWA), where the entirety of an individual's DNA is examined to look for the genomic mutations or variants which can cause health problems is a massively useful technology for diagnosing disease. ...

Genetics created May 16, 2013 | popularity not rated yet | comments 0


A molecular explanation for age-related fertility decline in women

(Medical Xpress)—Scientists supported by the National Institutes of Health have a new theory as to why a woman's fertility declines after her mid-30s. They also suggest an approach that might help slow ...

Medical researchers discover new ways to target, develop and design drugs to prevent and treat viral infection

Researchers at the University of Alberta have discovered a new drug target, developed a new drug and identified a new way to design drugs—all of which could be a winning combination in the battle against viruses.

Cancer survivors need more support to stop smoking and drinking

Cancer survivors are no more likely to stop smoking, cut down on alcohol, or exercise more often than the general population, according to new research published in the British Journal of Cancer today (Wednesday)

Alcohol sales fall due to ban on multi-buy promotions

(Medical Xpress)—A report published today shows a 2.6% decrease in the amount of alcohol sold per adult in Scotland in the year following the introduction of the Alcohol etc. (Scotland) Act in October 2011.

Facing the chill wind of blood pressure

(Medical Xpress)—High blood pressure is something that has traditionally been a problem in Scotland, but might there be a link to our climate?

Ethicists' behavior not more moral, study finds

(Medical Xpress)—Do ethicists engage in better moral behavior than other professors? The answer is no. Nor are they more likely than nonethicists to act according to values they espouse, according to researchers from the ...