The war against cancer is fought on many fronts. Surgery, drugs, preventative vaccinations, support for healthier lifestyles, and palliative care are crucial in the battle against this terrible disease. Genetic alteration is another tool in use and it has been showing some promising new results. The latest one has cancer cells turning on and killing off their own siblings.

The experimental approach uses a gene-editing technique known as CRISPR to reprogram cancer cells that have departed the original tumor to actually go back home and kill the tumor from which they originated. These “homing assassins” have been tested successfully in three different malignant tumors in mice. The results are published in the Journal of Translational Medicine.

"This is just the tip of the iceberg," said corresponding author Dr Khalid Shah from Harvard Medical School and Harvard Stem Cell Institute in a statement. "Cell-based therapies hold tremendous promise for delivering therapeutic agents to tumors and may provide treatment options where standard therapy has failed.

"With our technique, we show it is possible to reverse-engineer a patient's own cancer cells and use them to treat cancer. We think this has many implications and could be applicable across all cancer cell types."

The team took advantage of many cancer cells’ self-homing ability. It's this ability that cancer uses to spread to other areas of the same organ, or to different organs. This is a “strength” of aggressive types of cancers that the team has been able to turn it into a weakness.

The team used two different approaches. The first used “off-the-shelf” tumor cells that were genetically engineered to have the subject’s immune fingerprint. The second approach instead had the cancer cells from the subject edited with therapeutic molecules inserted in. Both approaches also had kill-switches given to the homing cancer cells.

The two approaches were tested in mouse models that suffered from primary brain cancer, recurrent brain cancer, and breast cancer that had spread to the brain. The team found evidence of the killer cells' success in eliminating tumors and showed that this treatment increases the survival of the mice.

"Our study demonstrates the therapeutic potential of using engineered tumor cells and their self-homing properties for developing receptor-targeted therapeutics for various cancers," added Shah.

The research is still in the early stage but it has a lot of potential.