A new study by researchers at the University of Rochester Medical Center in the United States has revealed that a key molecule can reprogram immune cells that normally protect the body from infection and cancer, turning them into harmful cells that promote cancer growth, preventing the immune system from defending the body and making it unable to eliminate invading cancer cells.
“Studying the behavior of these (pro-tumor) immune cells is important because they may be targets for treatments that block their harmful activity,” said Dr. Minsoo Kim, co-author of the study and research leader at the Wilmoth Cancer Institute, according to EurekAlert. The results of the study were published in the journal PNAS on August 23.
Kim led a team of scientists to study the dynamic interactions that occur between cells in the tumor environment, and the underlying factors that cause the harmful transformation of immune cells from good to bad.
platelet activating factor
Platelet-activating factor (PAF) was first identified for its ability to stimulate platelet aggregation and dilate blood vessels. It is now also known as a potent mediator of inflammation, allergic responses, and shock. PAF causes severe inflammation of the airways, leading to symptoms similar to asthma.
The production of platelet activating factor is stimulated by toxins produced by the destructive bacteria fragments, which leads to vasodilation and a drop in blood pressure, which results in decreased heart pumping and shock. Platelet activating factor is also associated with many medical conditions such as asthma, stroke, myocardial infarction, some tumors and cancers, and many other inflammatory conditions.
Researchers have found that platelet activating factor is a key molecule that controls the fate of immune cells.
From protecting the body to harming it
Not only does PAF recruit pro-cancer cells, it also suppresses the immune system’s ability to fight back. In addition, they discovered that many types of cancer depend on PAF signals.
“That’s what might be most important, because if we find a treatment that can interfere with platelet-activating factor, it could apply to many types of cancer,” said Kim, who is also a professor of microbiology and immunology at the University of Rochester Medical Center.
Much of the team’s work has focused on pancreatic cancer cells. This is one of the most deadly types of cancer, with a five-year survival rate of about 12 percent, and it is difficult to treat because pancreatic tumors are surrounded by a toxic cocktail of proteins and other tissues that protect the cancer from the immune system’s normal role in attacking invaders.