Understanding which cells give rise to which areas of cancer can improve our understanding of how a tumour has grown and developed, including how it has changed genetically, over time. This has been made possible using a new technique called spatial transcriptomics, which allows scientists to see what genetic changes take place without breaking up the tissue they’re looking at. This adds a new dimension which researchers have now used to reveal which cells have mutated and where within the ecosystem of an organ.
Current techniques for studying the genetics of cells within tumours involve taking a sample from the cancerous area and analysing the DNA of those cells. The problem is that many cancers, such as prostate cancer, are three dimensional, which means that any one sample would only give a small snapshot of the tumour.
In a new study published in Nature, the researchers used spatial transcriptomics to create a cross-sectional map of a whole prostate, including areas of healthy and cancerous cells. By grouping cells according to similar genetic identity, they were surprised to see areas of supposedly healthy tissue that already had many of the genetic characteristics of cancer. This finding was surprising because of both the genetic variability within the tissue as well as the large number of cells that would be considered healthy, but which contained mutations usually identified with cancerous cells.