Summary
Mayo Clinic researchers found genetic and cellular clues, including missing a gene and “zombie cells”, that help explain why some lung tumors respond well to immunotherapy.
A new Mayo Clinic study helps explain why some lung tumors respond well to immunotherapy while others do not. Immunotherapy drugs called immune checkpoint inhibitors or ICIs can help the body’s immune system attack cancer, but they work for only some patients with lung adenocarcinoma, the most common type of lung cancer.
Researchers led by Alan P. Fields, Ph.D., found that tumors with only one copy of a cancer-promoting gene called PRKCI behave differently from tumors with two copies. About 1 in 5 lung adenocarcinoma tumors have just one copy of this gene.
When the PRKCI gene is missing, these tumors grow more slowly and trigger a stronger immune response. That means the immune system can better recognize and attack the cancer when immunotherapy is used. The team also found that senescent tumor cells, sometimes called “zombie cells”, actually help stimulate the immune system in these cases. Even though these cells are usually linked to aging and disease, here they seem to help the body react more strongly to the tumor.
Another sign of a good response was the presence of clusters of immune cells in and around tumors. These clusters show that the immune system is active and ready to help fight the cancer.
The findings may help doctors identify which patients are most likely to benefit from immunotherapy. The researchers also noted that drugs that block PRKCI signaling might make other tumors behave more like the ones that respond well, offering a possible new combination approach in the future.
Scientists are learning what makes some lung cancers respond better to immunotherapy and that knowledge could help many patients get more benefit from these powerful treatments.
