Aggressive Cancers Spread Through Stored Energy

Aggressive cancers store glycogen in large amounts, which provides them with the energy to grow and spread according to a study published in PLOS ONE.

“We wondered if a cancer cell that wants to change its function can redirect energy not because it takes on new energy but because it has a stored reservoir of potential energy,” says Sofia D. Merajver, M.D., Ph.D., professor of internal medicine and epidemiology at the University of Michigan and a researcher at the University of Michigan Rogel Cancer Center in a press release about the study.

The researchers examined levels of glycogen stored in glucose molecules of triple-negative breast cancer, which represent a stored collection of glucose molecules. They used knocked down glycogen phosphorylase B (PYGB) in breast cancer cells and discovered that cells could not use these energy stores. They did not see the same effect in the normal breast cells.

“It was surprising just how much glycogen these cancer cells were storing,” Dr. Merajver says. “This means the cancer has that whole amount of glycogen ready to break down into glucose molecules when the need arises.”

Moreover, the researchers found that an enzyme controlling glycogen declined in the brain played a key role in glycogen control in breast cancer. The enzyme PYG exists in several forms, including brain and liver. PYGB is primarily expressed in the brain.

“This is a completely new way to look at the plasticity of breast cancer cells,” Dr. Merajver continued in the press release. “We think that this ability to change, for breast cancer cells to rewire themselves depending on their environment, is why many patients become resistant to precision medicines. Our study shows one way the cancer cells do this is by creating a reservoir of building blocks or energy.”