Multiple myeloma is a type of bone marrow cancer that mainly affects people over the age of 60 and in many cases cannot be cured. Researchers at the University Hospital of Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now found a new approach for a possible therapy of this cancer.
Multiple myeloma occurs when a certain type of white blood cell, called B cells, multiplies uncontrollably in the blood. As a result, bones are destroyed and patients also suffer from anemia, chronic infections and kidney problems. Although several effective chemotherapies are available, about one-third of patients do not respond to available treatments. Even if the treatment works, the tumor is not cured, but may eventually return. It was already known that the scavenger cells of the immune system, which are actually important for the defense against invaders in the body, work for the tumor in multiple myeloma. They support inflammation and thus promote tumor survival and growth.
The study by the FAU research team led by PD Dr. Heiko in cooperation with scientists from Milan has now discovered what happens at the molecular level when the phagocytes release inflammatory signals in the bone marrow. A blood component called beta-2-microglobulin seems to play an important role in this process. This is because the more severely the bone cancer has affected the body, the more of this protein is detectable in the patients’ blood. The Erlangen team now discovered that this is not just a side effect of the disease, but that this protein causes the phagocytes to exacerbate the disease. This is because the protein is devoured by the phagocytes – but not digested and broken down. In a sense, it is heavy on the stomach of the phagocytes, which causes them to send inflammatory signals that in turn benefit the tumor and its harmful effects in the body. The research team was able to demonstrate that cancer can be significantly mitigated if they succeed in blocking these inflammatory signals.
Dr. Heiko Bruns summarizes: “Phagocytes, macrophages, are essential cells to defend our organism against tumorigenesis. Many tumors can break through this line of defense because they manage to evade macrophage activity. We have seen that multiple myeloma employs an even more subtle strategy: It plays macrophage activity to its own advantage. Understanding how multiple myeloma achieves this is extremely relevant. Targeted blocking of the inflammasome could be a new adjuvant therapy strategy for patients in the future.”
Original publication:
DOI: 10.1016/j.immuni.2021.07.002
