CRISPR-Cas9 is a very useful tool for gene editing. It allows us to precisely and inexpensively edit an organism’s genes. You can read more about it here.
A recent study used it for something different though with great results. Instead of attempting to treat tumours in mice with this technology, hoping that someday this therapy would be used to treat humans, they instead used this technology to create tumours in mice.
Why would such thing be good, or important?
Right now we use mouse as models, to test various things on them and determine their effect. This may include genetic tools, drugs, therapies etc. But when we want to make a mouse have cancer for example so that we can attempt to treat that cancer with a new drug and thus determine this drug’s effectiveness the methods we use are a bit outdated.
Making accurate tumour “models”.
This is what this team of researchers did. They developed tumours in mice that better represent human tumours. They replicated the exact same mutations present in human tumours in mice, and developed a versatile mouse model to edit genes in vivo that in turn will generate more accurate representation of human tumours in mice. This will lead in better testing of drugs, with results that will hopefully be more equal/representative to those that will be found in clinical trials. Such a technology/method is very important as at the moment animal testing and results differ a lot from the results that are later obtained in clinical trials involving humans.
How does this work? Which genes are altered and how?
A CRISPR-Cas9 system is transferred in vivo in a RCAS-TVA vector system. In appropriate mice, gRNAs were used that affect the tumour suppressor genes, Trp53, Cdkn2a and Pten. Other genes were additionally altered to ensure an accurate tumour model in vivo. For more details you can read the full article online found in the sources bellow.