The new research suggests that triple-negative breast cancer cells have a sneaky way of stealing energy. They form tiny, straw-like structures, called gap junctions, that poke into nearby fat cells. Through these “straws,” the tumor cells suck out lipids, fatty molecules that the body typically uses for storing energy.

Dr. Jeremy Williams, the study’s lead author and a postdoctoral researcher at the University of California, San Francisco, explained it this way:

“Aggressive cancer cells can co-opt different nutrient sources to help them grow, including by stimulating fat cells in the breast to release their lipids. In the future, new treatments might starve the tumor cells by preventing their access to lipids from neighboring cells.”

In other words, these tumors are not just living off the patient’s blood supply. They are directly tapping into nearby fat cells for extra fuel.

The study combined experiments using human breast cancer tissue samples and mouse models.

1. In human tissue experiments:

• The researchers looked at fat cells at different distances from the tumor cells.
• They found that the fat cells closest to the tumor were severely depleted of lipids, while those farther away had more stored fat. This showed that the tumor was literally draining the fat cells.

2. In mouse experiments:

• Researchers genetically tweaked breast cancer cells so they could no longer form the straw-like gap junctions.
• The tumors stopped growing when these modified tumor cells were implanted into mice.
• In fact, just knocking out one gene was enough to block tumor progression.

This was strong evidence that the gap junction “straws” are crucial for cancer cells’ survival.