Punch a hole in the tumor's defense against the immune system
Our immune system is able to fight not only infections, but also tumor cells. Usually she succeeds: there are many malignant cells, but most of them are destroyed before they form a tumor. But if the first line of defense did not work, and the cancer still started, the tumor begins to defend itself from immune cells. Cambridge University scientists have identified a protein by which a tumor suppresses the host's immunity. Based on this research, new cancer treatment strategies can be developed.
One of the key areas of the fight against cancer today is the creation of so–called antitumor vaccines, that is, drugs that activate the immune system and direct it to fight malignant cells. Successes in this area have been repeatedly announced, but so far anti-cancer vaccination has not been highly effective. In a recent study published in Science, it turned out that the reason for this is the fibroblast activation protein alpha (FAP, fibroblast activation protein alpha). Normally, this protein stimulates the growth of connective tissue (for example, promotes wound healing), but in addition, as it turned out, FAP is produced by tumor stromal cells (connective tissue that supports the tumor and the blood vessels that feed it) and plays an important role in suppressing the immune response against cancerous tumors. If the stromal cells of the tumor are destroyed, then the suppression of anti-cancer immunity is "removed", and the immune system begins to suppress previously uncontrolled tumors.
Douglas Feron, professor of immunology at the University of Cambridge School of Medicine, one of the authors of the study, says: "The detection of specific cells that prevent an immune response within the complex complex of the cancer stroma is an important step. Further study of how these cells carry out their actions may contribute to improving immunological therapy, allowing us to overcome the barrier that cancer builds."
It has been shown that vaccines aimed at inducing the immune system to attack cancer cells in tumors are able to activate the immune response, but inexplicably almost never affect the growth of tumors. Experts in the field of anti-cancer immunity suspected that something in the tumor microenvironment suppresses the activity of immune cells. However, there were no ways to combat such suppression.
Cambridge University scientists have shown that stromal cells of many types of tumors, for example, breast and rectal cancers, actively express the FAP protein. To determine the specific role of stromal cells and the protein they produce in the resistance of cancer tumors to vaccination, the researchers created transgenic mice in which stromal cells producing FAP could be selectively destroyed. It turned out that if these cells (only 2% of the tumor) stop working, then mice with Lewis lung carcinoma recover quickly, as immune cells begin to actively fight the tumor.
Feron says that now it is necessary to find out whether these data are correct for a person. "These studies were performed on mice, and although there are many similarities between the immune systems of mice and humans, we cannot yet be sure that the data on the role of FAP are correct for humans. It is necessary to suppress the work of stromal cells in the patient's tumor in order to talk about it." This is reported by Informnauka with reference to ScienceDaily: Breakthrough in Cancer Vaccine Research.
Portal "Eternal youth" http://vechnayamolodost.ru22.11.2010