White Blood Cells Can Help Prevent Cancer

By Jane Farrell

Belgian researchers have discovered that a type of white blood cell can be “fine-tuned” to help prevent the spread of cancer.

The team of scientists at VIB and KU Leuven, led by professor Massimiliano Mazzone, demonstrated that the metabolism of macrophages, a particular type of white blood cell, can be attuned to prevent the spread of cancer. The key is in making these macrophages more prone to ‘steal’ sugar from the cells forming the tumor’s blood vessels. As a result, these blood vessels will be structured more tightly, which can prevent cancer cells from spreading to other organs.

The research was published in the journal Cell Metabolism.

Macrophages attack foreign micro-organisms and remove harmful substances within the body. As a result, they are an essential part of our immune system. On top of their positive effect on pathogens, macrophages can also play a negative role in cancer biology. Indeed, tumors contain a lot of specific macrophages that play a decisive role in the formation of blood vessels. In tumors, these vessels traditionally have a chaotic and dysfunctional buildup. As a result, cancer cells are more likely to escape through the vessels, enter the bloodstream and invade other organs.

While properties of macrophages have already been studied extensively, it remained unknown whether changing their metabolism would impact their functions.. Mazzone and Dr. Mathias Wenes investigated this by blocking a specific gene called REDD1 in the macrophages. This stimulated the cells’ glycolysis, the process by which they convert sugar into energy.

“The supply of glucose to a tumor has a negative effect, comparable to giving too much sugar to a child: it causes hyper-activation of many cellular compartments,” Mazzone explained. More specifically, the cells that are forming the blood vessels are getting out of control by this glucose overload. They quickly give shape to a chaotic, irregular vessel network typical to cancer.

“By changing the macrophages’ metabolism, we actually set up a ‘glucose competition’ between the macrophages and the tumor’s blood vessels. As a result, the macrophages can eat the glucose instead of the blood vessel cells. Because the latter are not overstimulated anymore, they are able to create vessels in a gentler way. This forms a structured and strong vessel barrier around the tumor, preventing cancer cells to escape to the bloodstream and invade distant organs.”