DNA

Although most cancer cases are considered sporadic, some are defined as hereditary, as certain individuals carry variants in their DNA that increase their risk. A team in the United States has analysed the genetic information of more than 400,000 people and concluded that the proportion of those with known risk variants is slightly higher than 5%. This figure is higher than expected: nearly double for variants of the BRCA1 or BRCA2 genes and between 10 and 20 times higher for variants related to thyroid cancer. The results are published in the journal JAMA in research letter format.

The very functioning of the cell itself or stresses such as those caused by sun exposure can cause breaks in our DNA, which must be repaired. A study developed by the CNIO has completed a catalog of how each of our genes affects the repair of some of these breaks and how they influence the resulting "scars." The catalog, which they have called the "human repairome," will be openly available. According to the researchers, whose work is published in Science, it will have "implications for human health, including the biology and treatment of cancer, as well as for efforts toward total control of CRISPR-Cas gene-editing technologies".

Although tobacco consumption is declining in many parts of the world, there appears to be an increase in the number of lung cancer cases among non-smokers. One of the possible causes of this increase is air pollution. Now, researchers in the US, with Spanish participation, have analysed the genomes of 871 lung tumours in people from various locations who had never smoked. The results, published in the journal Nature, indicate that greater exposure to pollution is linked to an increase in the number of mutations, including those commonly associated with tobacco.

An international team, co-led by researchers from the CNAG in Barcelona, has developed a new technique that allows millions of individual cells to be analysed at the same time without the need for sequencing, using what is known as spatial genomics. The technique, called STAMP, could make this type of analysis cheaper and more widespread. ‘We are opening the door to revolutionary advances in precision medicine, enabling the development of highly targeted diagnostics and therapies capable of transforming clinical outcomes,’ say the authors, who publish their findings in the journal Cell.

Extrachromosomal DNA circles are structures that appear floating in the nucleus of cells in some tumours and are associated with a poor prognosis. Now, an international team has studied the mechanism by which they could contribute to the aggressiveness of pancreatic cancer. The circles may contain an oncogene called Myc that promotes growth. Furthermore, their quantity increases or decreases to adapt to the environment. Although they were only observed in 15% of the cases studied, the discovery could open up new possibilities for treatment, according to the authors. The results are published in the journal Nature.

Living as a private renter is associated with faster biological ageing than owning a home, according to a study using a UK database with data available on 1,420 people. The team, whose research is published in the Journal of Epidemiology and Community Health, used DNA methylation data - chemical modifications - to measure people's biological age, and says this correlation is stronger than the association between biological ageing and unemployment, or having been a smoker. Apart from blood samples from the database, the research also used historical data from a national survey.