July 8, 2024 For more information, contact : Nicole Fawcett, [email protected] 734-764-2220 Newswise — ANN ARBOR, Michigan — To understand why some cancers successfully circumvent the immune system to grow unchecked, researchers turned to pregnancy. “In pregnancy, the immune system does not reject the growing fetus, so we know there must be mechanisms active in the placenta. In cancer, it’s the same thing: the growing tumor is not rejected by the immune system.
It means the cancer cells have developed strategies to suppress immune rejection, same as in pregnancy,” said Weiping Zou, M.D., Ph.
D. It’s a good thing in pregnancy – it allows the baby to grow. But in cancer, it means the tumor grows unchecked and treatments meant to stimulate an immune response are not effective.
To understand this overlap, Zou collaborated with other researchers from the University of Michigan Rogel Cancer Center – bringing together unique expertise in immunology, cancer genetics, gynecologic pathology and medicinal chemistry. They found that indeed there is a molecular mechanism shared in cancer and pregnancy that suppresses the immune system . Block this mechanism, called B7-H4, and the immune system revs up to slow cancer’s growth.
Looking at mouse models and cell lines of breast and gynecologic cancers, the researchers identified the hormone progesterone as a key regulator of the B7-H4 immune checkpoint. The paper is published in Cell . B7-H4 expression has previously been ass.