While it is known that cancers contain subclones,
this is the first time that anyone has shown that each cell in a tumor is
different.
‘Single-cell and organoid technology enable scientists to study cancer-specific processes.’
Prof Hans Clevers, from Hubrecht Institute in the
Netherlands, the joint corresponding author on the paper, said: "Organoids
had not been used to study single cancer cells before. Nobuo Sasaki,
in my lab isolated multiple single cells from the tumors and grew them up as
organoids. This enabled us to study each cell without the errors that
standard single cell methods bring. For the first time ever, we could
make a really comprehensive comparison of individual normal and tumor cells
from the exact same type of tissue, taken at the same time, from the same
person, and see how the cancer had developed."
Study Highlights
- Every tumor is different, and every cell within the tumor is
also genetically unique.
- Mutational process in tumor cells is more than normal cells,
leading to a huge increase in mutation rate for tumors compared with
normal cells.
- The high mutation rate may be responsible for the high genetic
diversity within the tumors.
- The mutation rate starts to change many years before the
diagnosis of the cancer. This time window may provide diagnostic
clues in the future, if it were possible to
identify the rise in mutation rate early in a cell.
Prof Sir Mike Stratton, the joint corresponding
author on the paper from the Wellcome Sanger Institute, said: "This study
gives us fundamental knowledge on the way cancers arise. By studying the
patterns of mutations from individual healthy and tumor cells, we can learn
what mutational processes have occurred, and then look to see what has caused
them. Extending our knowledge on the origin of these processes could help us
discover new risk factors to reduce the incidence of cancer, and could also put
us in a better position to create drugs to target cancer-specific mutational
processes directly."
Source: Medindia
