The enzyme TET1 directs us through fetal development and battling cancer

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To ensure normal fetal development and prevention of diseases, it is crucial that certain genes turn on or off in the proper time intervals. University of Copenhagen, have now shown in Professor Kristian Helin group BRIC and Centre for epigenetics, researchers, such as the TET1 enzyme controls the activity of our genes. The results were published in the journal nature.

Control over our genes

The complete human genetic code was assigned to the year 2000. However, has become clear that the genetic code can answer even partially, as an individual developed and is being protected from disease. What is is harmful as our genes are controlled - also what enabled genes or at certain times are disabled. This is regulated in part certain cellular enzymes which can small chemical groups, methyl groups, on our DNA:

"The methyl groups can disable the gene which is located in a stretch of DNA in which it is added." TET1 is another type of enzyme, which can fine-tune the signals, "The control gene activity by modifying the methyl groups are then removed, says Kristian Helin."

TET1 controls fetal development

Kristine Williams, Jesper Christensen, and Marianne Terndrup Pedersen are the 3 most important people in the laboratory contribute Helin at the BRIC with the new results:

"Our main finding is that TET1 behaving like a safe guard and prevents that methyl groups are connected to genes, which must be active for normal growth and development of our cells." This is crucial for normal fetal development, "says PhD student of Kristine Williams." Selected genes must be active in the stem cells of our body, before the cells to one of the more than 200 specialized cell types are specialized, that are present in our body. Other genes must be active only in specialized cell types such as such as the liver cells, muscle cells, or neurons.

When cancer cells develop

The results are also to understand what goes wrong, if some cells to develop accidentally in cancer cells. The functions of our body are subject to constant cell renewal by dividing the cells. A large cellular machinery makes sure that our DNA intact and is correct, copied when our cells divide. This is essential for the normal development and function of cells. In the worst case result in changes in the DNA, so-called mutations, development of cancer. Specific genes called suppressor are particularly important for the fight against cancer:

"When the methyl groups are provided to genes that are normally active in normal cells, the genes are disabled and this can be harmful." If it happens to suppressor, there can be development a step towards cancer as that genes can no longer protection against unintentional cell growth, "says Kristian Helin."

TET enzymes and blood cancers

So TET1 can fight cancer, by controlling the activity and protective function of the suppressor. Our cells contain also a close relative to the TET1, the TET2 enzyme, which is the most common mutant gene in blood cancers. The research on BRIC has discovered that TET2 also controls the gene activity by facilitating removing methyl groups from the DNA and they currently these studies to the cellular models for cancer development expand. Results from these studies, gain insight into the mechanisms for blood cancers and can potentially lead to development of new Therapeutics.

Original paper: "TET1 and Hydroxymethylcytosine in transcription and DNA methylation fidelity", Williams et al., nature 13 April 2011

Source:
Kristian Helin
University of Copenhagen