In a new study from GIMM, researchers show that even in environments with very different levels of nutrients, cells consistently find surprisingly similar genetic solutions to problems in DNA replication – a vital process whose dysregulation is often linked to cancer.
Accurately copying DNA before every cell division is essential for life. But when this process goes wrong – something that happens often in cancer – cells experience stress and must find ways to survive. A new study from the Genome Maintenance and Evolution Lab, published in Molecular Systems Biology, reveals that cells facing these challenges tend to evolve almost identical genetic fixes, regardless of the surrounding conditions.
In this work, the researchers wanted to understand whether the amount of sugar (glucose) in the environment changes the way cells adapt to so-called “DNA replication stress” – a situation where cells struggle to copy their DNA properly. To do this, they used yeast, a simple organism that shares many features with human cells, and tracked its evolution over 1,000 generations (the equivalent of several years of cell divisions in humans).
Glucose levels changed how much cells struggled with the DNA replication problem and how quickly they adapted, but not the genetic solutions they evolved to cope with it. In other words, no matter how much sugar was available, the same mutations kept appearing in specific groups of genes. These mutations are linked to chromosome organization, DNA replication itself, the response to genetic damage, and even a complex that controls how genes are switched on.
“It was fascinating to see how similar the solutions were, despite such different environments,” says Mariana Natalino, first author of the study. “These patterns could help us anticipate how certain diseases adapt and resist treatment.”
Since some tumours also face replication stress and variable nutrient supplies, understanding these common evolutionary paths could be key to predicting – and perhaps preventing – the genetic changes that allow cancer to grow or become resistant to therapies.
