Scientists use gene editing technology to shrink cancer
Scientists are able to reprogram a signal that promotes tumor growth into one that shrinks it instead by using gene editing. A team from the First Affiliated Hospital of Shenzhen University, China demonstrated in their study, published in Nature Methods, how they could stop the growth of cancer in cells by modifying part of the CRISPR–Cas9 system.
CRISPR-Cas9 is a gene editing platform that is currently being looked at as a means of providing treatments for diseases by targeting cells. Cas9 is an enzyme that cuts a double DNA strand at a point, while CRISPR is a chemical messenger. The latter can guide Cas9 so it binds with a specific part of the genome – meaning scientists can disrupt, edit or insert a new sequence to make it have a new function.
In their study, the team used this gene editing technique to target eukaryotic cells. They receive signals to regulate their gene expression.
Scientists manipulated the signaling pathway to regulate gene expression at the site. They modified the component so it became activated by a signal that normally promotes tumor growth. They then brought in two tumor suppressor genes, meaning cancer cells would not grow.
In experiments with mice, they found their technique had an anticancer effect. Cancer cells were injected into mice and after several days, tumors developed. Treated mice were found to have “dramatically smaller” tumors than the control mice.
The experts say the study is promising but remains unclear whether it would work in humans. The editing process itself also presents risks as too much DNA can be cut out. These unwanted or ‘off-target’ edits could then result in alteration of other important genes that may inadvertently trigger cancer, for example.
Chris Lord, from the Institute of Cancer Research, added: “It’s an interesting idea: using the fundamental nature of a tumor cell to activate a ‘suicide’ program. The key to translating this technique into the clinic will be to see how specific to the tumor cell the CRISPR activation will be and how specific, in terms of genes, the CRISPR mediated gene cutting will be.
“These are essentially the same two issues you have with all cancer treatments – how specific for the tumor cell and how specific for the target,”he said, adding that a lot more research is needed before the technique can be tested on humans so it will be a long time before patients benefit from this advancing technology.
