Scientists have discovered why cancer cells don’t kill themselves

© Fotolia / crevisРаковая cell in the human bodyScientists have discovered why cancer cells don’t kill themselves© Fotolia / crevis

The secret to the survival of many cancers is that they use the «fifth Collon» in their own DNA, to suppress the operation of the system of self-destruction of cells, according to a paper published in the journal Nature Communications.

«Due to this discovery we can now use the same algorithm to check for broken mechanism in the DNA of tumours in patients participating in the project «100 thousands of genomes». These observations may help us to find new methods of combating cancer, which will save the lives of more people in the future,» says Christopher Yau (Christopher Yau) the University of Birmingham (UK).

A considerable part of tumors in humans and animals occurs because of a failure in the gene p53. He is responsible for the synthesis of a protein that monitors the integrity of genetic information and includes a self-destruct mechanism — apoptosis in case of serious breakdowns. Cells with damaged p53 is extremely difficult to suppress due to the lack of «program of self-destruction» in their genome.

Recent studies show that many cancer cells have no fatal mutations in the gene p53, but also contain many other DNA damage that would normally cause it to enter, says Yau. Such cells are also difficult to treat, as conventional methods of cancer control, including the destruction of DNA using radiation or chemotherapy, do not force them to «commit suicide».

British biologists have figured out why this happens by studying the genomes of several hundred varieties of ovarian cancer. Initially, scientists tried to understand what mutations make a cancer more aggressive, they have correlated sets of mutations for each tumor, and allocated to those that most strongly affect the behavior of cancer cells.

It turned out that about a fifth of the tumors, a very large number by the standards of the cancer mysteriously did not have mutations in the genes related to the work of a special system that prevents the Assembly of protein molecules when reading damaged genes.

This system, a set of several utility of proteins and ribosomes, the cellular «protein factories», starts after the kernel finds the gene and prepare the so-called «messenger RNA». It is a short pattern of «letters» of the genetic code that contains instructions for the collection of protein molecules.

Before mRNA leaves the nucleus, joined by special proteins-«the inspectors» of the family of UPF, who check whether it contains any meaningless typos leading to unexpected termination of protein synthesis. If such defects in the mRNA is, the proteins are firmly attached to a RNA molecule that interferes with the ribosome reads it, leading to its subsequent destruction.

How do you think Yau and his colleagues, correct operation of the system «genetic check spelling» in cancer cells, not killing them, but rather helps to survive. This is because proteins UPF to block the readout of the p53 gene and prevent it to work even if it contains even a relatively harmless mutations.

Discovering such an unexpected survival mechanism of ovarian cancer, the researchers tried to find its analogues in cell cultures of other types of cancer. After analyzing more than seven thousand other tumors, biologists found hundreds of other examples of how this system helps the cancer to survive.

Therefore, Yau and his colleagues propose to create a drug that would block the «genetic check spelling» in the cancer cells and allow p53 to run a program of cellular suicide. Such substances, as scientists believe, could save the lives of many thousands of people whose cancer is now considered «unbreakable» for the action of classical treatments.

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