These connections can be found almost everywhere: in exhaust gases of vehicles, smoke, building materials and materials for furniture production, and even in cosmetics and shampoos. We are talking about aldehydes. They are reported in a new study, breaking the ability of DNA to repair itself and therefore increase the risk of developing cancer. The work was published in the journal Cell.
Normal aldehydes are synthesized in the human body in small amount. But their number in the environment is growing. Earlier it was reported about the relationship between these substances and the likelihood of developing cancer, but the mechanisms underlying this relationship were unclear.
New research was conducted under the guidance of Professor Ashok Venkitaraman (Ashok Venkitaraman), head of cancer division, medical research Council (Medical Research Council, MRC), University of Cambridge (University of Cambridge). Scientists used a culture of normal human cells and cells obtained from patients carriers of mutations of the BRCA2 gene associated with breast cancer. It turned out that aldehydes disrupt the ability of DNA to repair itself even in normal healthy cells, and mutation in the BRCA2 gene are particularly sensitive to such damage.
Most genes in our cells are present in two copies. The people who inherited a single mutated copy of the gene BRCA2 have an increased risk of developing breast cancer. The reasons for this are not entirely clear, because one of the copies of the gene in carriers of mutations is normal, and the cells of their body can still produce the protein BRCA2 to repair DNA, albeit in smaller quantities.
As shown by the results of a new study, aldehydes lead to the destruction of BRCA2 protein inside cells. If a person there is a mutation in the corresponding gene, the concentration necessary for DNA repair protein fall below the threshold values. That is, the protein becomes less than necessary in order to protect the genetic material from the accumulation of “failures.”
It is believed that the mutation in the BRCA2 gene account for about 1% of the General population. These people are at risk of developing cancer of the breast, ovaries, prostate and pancreas. Contact with aldehydes further increases the likelihood that they have a malignant tumor.
“Our study shows how the chemical compounds with which we increasingly encounter in everyday life can increase the risk of developing diseases such as cancer, says Professor Venkitaraman. It also demonstrates why the “failed stars” — the birth of with defined mutations can make some people particularly susceptible to the influence of carcinogens”.
One of the most common sources of aldehydes is an alcohol. Our body turns the alcohol we drink to acetaldehyde. Normally, this aldehyde is cleaved by the enzyme acetyldihydrocodeine. However, about 500 million inhabitants of the planet (mainly inhabitants of Japan, China, Korea and other Eastern countries) are carriers of the ALDH2 gene mutation, inactivating this enzyme. That is why many Asians feel the heat in the body when you drink alcohol. But it could mean that these people are particularly susceptible to the carcinogenic effect of aldehydes.
A new study demonstrates that carriers of mutations of the gene ALDH2 (which is 30-60% of the population of Japan, Korea and China) sensitivity to the carcinogenic effects of aldehydes is increased regardless of the presence of mutations in the BRCA2 gene. So, these people also are at risk for the development of a number of varieties of cancer.