Immunotherapy is an increasingly powerful form of cancer treatment in which the patient’s own immune system has an enhanced resistance to disease, a promising type of treatment called epithettherapy. This involves using a changed version of the patient’s own cells to trigger a stronger response from their own immune system. Scientists at the Johns Hopkins Kimmel Cancer Center have reported an exciting development in the field, showing that genetically edited bone marrow cells can slow the growth of prostate and pancreatic cancers in mice.
The study builds on previous studies in which scientists have shown that a variety of cancers, including melanoma, colon and brain cancers, grow much more slowly in mice lacking a specific gene called p50, which appears to activate a stronger immune response. Researchers at Johns Hopkins University are trying to further validate these early findings while expanding the usefulness of promising cancer treatments.
To do this, the team used so-called immature myelin-like cells, a type of white blood cell. Previous studies have shown that this white blood cell can help turn on the immune response to tumors. In this case, immature myelin cells were taken from the bone marrow of mice that lacked the p50 gene as a way to compare their cellular behavior with those with the p50 gene.
The team vaccinated human prostate cancer and pancreatic cancer cells on mice with p50 defects and another group of normal mice. Both groups were pre-treated with a common cancer drug called 5-fluoromyllaquine, and the team found that when combined with myelin-like cells that lacked p50, it produced significantly better results.
In these mice, tumors grew at least three times slower in 13 of the 14 pancreatic cancers (93%) and 8 of the 15 pancreatic cancers (53%). In some cases, combination therapy caused a significant retreat in pancreatic cancer mice, and the tumor was even one-tenth the size of the tumor, which scientists called “significant.”
These results further suggest that p50-deficient myelin cells can benefit from a range of cancer treatments by stimulating the body’s immune system to function. Study co-author and pediatric oncologist Alan Friedman said: “The seven different types of cancerweds we tested – prostate cancer, pancreatic cancer, brain cancer, melanoma, colon cancer, sarcoma and neuroblastoma – grew slower in mice without p50. “
The study was published in the journal Journal for The Atherapy of Cancer.