While the causes of bladder cancer remain largely unknown, smoking is considered to be the main risk factor for the disease. By recreating the DNA damage caused by smoking toxins, these scientists at York University will help to better understand the causes of bladder cancer.
The team, led by Dr. Simon Baker of the Department of Biology at the University of York, cultivated human bladder tissue in the laboratory and exposed it to a common toxin from cigarette smoke. After the tissues were damaged by the toxins from the smoke, the team analyzed the 2 billion letters of the genetic code (DNA) to identify a pattern of change or “mutational signature”.
Identification of a mutational signature of tobacco-related cell damage
This mutational signature consists of a unique pattern of DNA damage that could be found in the event of the development of bladder cancer in connection with smoking: “Mutational signatures can be used as fingerprints on a stage. crime. When we analyze DNA in cancer, we can identify these fingerprints and therefore find the criminals involved in the damage that led to cancer. ”
Weigh the importance of the different risk factors: the study reveals that the toxins from tobacco smoke do leave a specific imprint on the DNA of bladder tissues grown in the laboratory. However, this mutational signature linked to smoke toxins appears, after an in-depth analysis of the tissues, only responsible for a small part of the damage. This is the second lesson of this study: the technique of biopsy analysis could, for a given tumor, make it possible to balance the incidence of different risk factors. Here, the researchers conclude that although smoking is the main risk factor for bladder cancer, direct damage to DNA by smoke toxins does not appear to be the main reason for the formation of these cancers.
The toxins from tobacco smoke could be triggers that accelerate other DNA damaging events. The enzymes called “APOBEC” could thus be involved in this cascade of events:
recent studies suggest that they may indeed mistakenly target our own DNA in a number of types of cancer and, in particular, in bladder cells.