In people with cancer, immune cells circulating in the bloodstream are often primed to attack tumor cells. However, tumors often develop an arsenal of tricks to hide from these immune cells. One technique is to make cancer-associated blood vessels impermeable to immune cells. As a consequence, immune cells cannot reach the tumor tissue and the cancer is empowered to grow undisturbed. The article by Prof. Griffioen and first author Dr. Else Huijbers, produced together with Drs. Kabir Khan and Robert Kerbel from the University of Toronto, Canada sheds light on how tumor cells take control over blood vessel walls.
Protected growth process
The same mechanism is vital for developing embryos. “When an embryo builds complex organs, it is an advantage to keep immune cells at bay,” explains Prof. Griffioen. “Therefore, the blood vessel wall is a secure barrier in developing embryos to restrict immune cells in the blood stream. An embryo has to grow very quickly in a short time to make a liver, a kidney or an eye, for example. Many new blood vessels are created to support this incredible growth spurt. At the same time, the developing embryo confines its immune system, because interference from immune cells is counterproductive. It is exactly this shielded embryonic growth process that tumors hijack.”
Holding off immune cells
Millions of years of evolution have ensured that blood vessels in the embryo prevent immune cells from entering the developing tissues. Dr. Huijbers: “By knowing how a tumor evades immune cells, researchers can develop more effective medicines to treat cancer.”
For more information contact Professor Arjan Griffioen (a.griffioen@amsterdamumc.nl) or read the article: Huijbers, E.J.M., et al. (2022) Tumors resurrect an embryonic vascular program to escape immunity. Science Immunology. DOI: 10.1126/sciimmunol.abm6388
Researchers involved at Cancer Center Amsterdam - Amsterdam UMC:
Dr. Else Huijbers
Professor Arjan Griffioen
Funding for this study was provided by the Dutch Cancer Society