Neuro oncology: surprise or not? Immune cells are the key factor in determining the growth rate of cancer cells

June 6, 2019 / BIOON / - when cells start to grow out of control, they will produce tumors But a new study finds that the speed of tumor growth does not just depend on the speed of cancer cell division Researchers at Washington University School of medicine in St Louis, USA, have studied brain tumors in mice and found that immune cells that could protect the body against disease are sometimes induced to help tumor cells The researchers found that the more immune cells tumors attract, the faster they grow Photo source: neuro oncology research results were published in the journal neuro oncology recently Studies have shown that the treatment of immune system cells may slow down the growth of brain tumors in people with type 1 neurofibromatosis (NF1) genetic disease "It's not just about tumor cells," said Dr David h Gutmann, Professor of Neurology and senior author of the study, director of the neurofibromatosis center at the University of Washington "This is also related to what happens in the tumor environment, which promotes the growth of brain cancer This gives us another way to attack these tumors, not just to kill them, but also to block the communication between tumor cells and immune system cells "Gutmann is also a professor of genetics, neurosurgery and pediatrics Although NF1 patients usually go to a doctor because of birthmarks on their skin, their risk of cancer increases One of the most common tumors in children is a low-grade brain tumor called optic gliomas, which affects the optic nerve that connects the brain to the eye, some of which cause vision loss Unfortunately, NF1 is a well-known variable disease Oncologists can't predict what kind of people will get cancer, how fast these tumors will grow, or what kind of medical problems they will cause It's hard for all doctors to decide when they need chemotherapy In order to better understand why some tumors grow faster than others, Xiao Fan Guo, the first author of the study and doctor of medicine of Gutmann laboratory, created five mouse strains with different gene mutations in the NF1 gene of mouse genome and other places These five mutants differ greatly in tumor development and growth Three of the strains of mice began to grow tumors at about 3 months old, and one of them grew very fast The fourth group of mice developed tumors at 6 months of age, while only a quarter of the fifth group developed brain tumors on the optic nerve When researchers isolated tumor cells from mice and cultured them in Petri dishes, they found that the growth rate of tumor cells was almost the same No matter what kind of mutation occurs in tumor cells, the growth rate of cancer cells is very similar to other characteristics There are two kinds of immune cells in the tumor, microglia and T cells Dr Guo and his colleagues found that tumor cells themselves are releasing immune system proteins that attract immune cells to tumors "The cells that were supposed to help the brain defend against tumors are now cells that help tumors grow "Said Gutmann Researchers are now trying to use this relationship between tumor cells and immune system cells to find new ways to treat brain tumors in patients with NF1 One strategy is to slow tumor growth by preventing microglia or T cells from supporting cancer cells However, a more ambitious strategy is to reprogram T cells so that they no longer help tumor cells grow "Our idea is to use T cells as Trojans," Gutmann said These are ongoing experiments: we are trying to change T cells so that when they enter the brain, they do not promote tumor growth, but inhibit tumor growth "Reference: Xiaofan Guo et al Genetic and general alternations differentiated low grade glioma growth through cancer stem cell specific chemokine acceptance of T cells and microglia, neuro Oncology (2019) Doi: 10.1093/neuronc/noz080