Immunotherapy is a form of cancer treatment that uses the power of the immune system to fight disease. The innovate protocols have given several patients more treatment options, and they’ve been successful healing many types of cancer. Unfortunately, one of the problems with immunotherapy, as with any cancer treatment, is that patients often experience relapses. Although doctors can’t say for sure why tumors come back, a Rockefeller University researcher believes she has determined which tumor cells are responsible for stopping immunotherapy and how exactly they accomplish it.
Elaine Fuchs, who is the Rebecca C. Lancefield Professor at Rockefeller, led a mouse model study in which the subjects had a type of squamous cell carcinoma cancer that typically responds to immunotherapy. The study was published in Cell. The team revealed their findings that a subset of cancer cells known as tumor-initiating stem cells withstand immunotherapy treatments by generating a molecule called CD80. This molecule lives on the surface of the cells and it weakens the power of the body’s immune cells that would normally destroy the cancer.
Yuxuan Miao, a post doctoral associate in Fuchs’ lab, said that “tumor-initiating stem cells make up less than two percent of a tumor’s mass, but they’re sneaky. They essentially quite the immune system to avoid elimination, then later regrow a whole new tumor.”
Fuchs and her team also discovered that the molecular switch that incites the cells to create CD80 in the first place is a protein called TGF beta. This information gives scientists the potential to improve immunotherapy in many ways. For instance, they could use antibodies that block TGF beta in combination with conventional immunotherapy drugs in order to conquer this issue of resistance.