According to a story from news-medical.net, scientists may have made a significant breakthrough discovery that could make cancer treatment more effective. The discovery involves a new method that breaks through the defenses of cancer tumors—a “wall” of sorts that the tumor uses to protect itself from treatment. By getting around this barrier, a cancer tumor could suddenly become vulnerable to the effects of immunotherapy-style drugs.
Myeloid-Derived Suppressor Cells
This study was supported by Cancer Research UK. While the process has only been achieved in the lab setting so far, it has the potential to make relatively new methods for treating cancer, such as CAR-T cell therapy, a viable option for solid tumor cancers. The basis of these cancer’s defenses are a special cell called myeloid-derived suppressor cells. These cells appear before any treatment has begun. They play a critical role in allowing a tumor to evade detection and attack from the immune system. They directly prevent T-cells from having any effect on a cancer tumor.
Generally a cancer patient that has a higher number of these cells is going to have a less favorable prognosis. Aside from their ability to resist treatment and avoid the immune system, they also make it easier for cancer to metastasize, or spread, to other parts of the body. In the study, the scientists found that there was a certain antibody drug, typically used to treat leukemia, that was capable of dispatching of myeloid-derived suppressor cells. The key to this discovery was determining which proteins are expressed on the surface of these cells. The CD33 protein was found to be prevalent on myeloid-derived suppressors in a diverse array of cancer types.
The antibody drug gentuzumab ozogamicin targets this protein specifically. It is typically used to treat acute myeloid leukemia, but the discovery of this capability means that the drug could suddenly have much greater utility. CAR-T cell therapy has had only limited impact on solid tumor cancers, but perhaps a combination of gentuzumab ozogamicin followed by CAR-T cell therapy could finally make this approach a real force to be reckoned within the world of solid tumor cancer treatment.
The discovery could also be of significant for a couple of other rare diseases: macrophage activation syndrome and hemophagocytic lymphohistiocytosis. These rare diseases are characterized by abnormal immune responses to a certain trigger, like an infection.
The original study was published in the journal EBioMedicine.