Gene-editing technique could speed up study of cancer mutations | MIT News | Massachusetts Institute of Technology

Good news! Cancer is history (soon)! This may have great potential!

"Genomic studies of cancer patients have revealed thousands of mutations linked to tumor development. However, for the vast majority of those mutations, researchers are unsure of how they contribute to cancer because there’s no easy way to study them in animal models. ...

researchers have created models of several different mutations of the cancer-causing gene Kras, in different organs. They believe this technique could also be used for nearly any other type of cancer mutation that has been identified.

Such models could help researchers identify and test new drugs that target these mutations. ...

To demonstrate the potential of this technique, the researchers engineered several different mutations into the Kras gene, which drives about 30 percent of all human cancers, including nearly all pancreatic adenocarcinomas. However, not all Kras mutations are identical. Many Kras mutations occur at a location known as G12, where the amino acid glycine is found, and depending on the mutation, this glycine can be converted into one of several different amino acids.

The researchers developed models of four different types of Kras mutations found in lung cancer: G12C, G12D, G12R, and G12A. To their surprise, they found that the tumors generated in each of these models had very different traits. For example, G12R mutations produced large, aggressive lung tumors, while G12A tumors were smaller and progressed more slowly. ...
Currently, there are only two FDA-approved drugs that target Kras mutations, and they are both specific to the G12C mutation, which accounts for about 30 percent of the Kras mutations seen in lung cancer. ...
The researchers also used their technique to create pancreatic organoids with several different types of mutations in the tumor suppressor gene p53, and they are now developing mouse models of these mutations. They are also working on generating models of additional Kras mutations, along with other mutations that help to confer resistance to Kras inhibitors. ..."

From the abstract:

"Genetically engineered mouse models only capture a small fraction of the genetic lesions that drive human cancer. Current CRISPR–Cas9 models can expand this fraction but are limited by their reliance on error-prone DNA repair. Here we develop a system for in vivo prime editing by encoding a Cre-inducible prime editor in the mouse germline. This model allows rapid, precise engineering of a wide range of mutations in cell lines and organoids derived from primary tissues, including a clinically relevant Kras mutation associated with drug resistance and Trp53 hotspot mutations commonly observed in pancreatic cancer. With this system, we demonstrate somatic prime editing in vivo using lipid nanoparticles, and we model lung and pancreatic cancer through viral delivery of prime editing guide RNAs or orthotopic transplantation of prime-edited organoids. We believe that this approach will accelerate functional studies of cancer-associated mutations and complex genetic combinations that are challenging to construct with traditional models."

Gene-editing technique could speed up study of cancer mutations | MIT News | Massachusetts Institute of Technology With the new method, scientists can explore many cancer mutations whose roles are unknown, helping them develop new drugs that target those mutations.

A prime editor mouse to model a broad spectrum of somatic mutations in vivo (no public access)