Breast tumors tunnel into fat cells to fuel up

When triple-negative breast cancer grows, the fat cells around it seem to shrink.  

The researchers have discovered that the cells of these tumors, which are among the deadliest types of breast cancer, build molecular tunnels, called gap junctions, into nearby fat cells. The tumor cells then send instructions that trigger the fat cells to release stores of energy that could feed the cancer.  

Blocking the gap junctions stopped tumors from growing.  

“Cancers thrive by hijacking the body’s energy sources and we’ve identified how this works in triple negative breast cancer,” said the senior author of the paper.  

The study appears in Nature Communications. 

The team made their discovery by analyzing fat and tumor cells from breast cancer patients, as well as laboratory models of breast cancer. 

The authors evaluated breast tumors and their normal adjacent tissue from several patient cohorts, patient-derived xenografts, and mouse models.

They observed that lipolysis and lipolytic signaling are activated in neighboring adipose tissue and find functional gap junctions form between breast cancer cells and adipocytes.

The researchers observed transfer of cAMP from breast cancer cells to adipocytes and activates lipolysis in a gap junction-dependent manner. They also find that connexin 31 (GJB3) promotes receptor triple negative breast cancer growth and activation of lipolysis in vivo. 

The findings have immediate clinical implications. Although no one is yet testing drugs that block gap junctions for breast cancer, there are ongoing clinical trials using these drugs for brain cancer.  

“This is a golden opportunity for us to develop effective strategies to treat the most aggressive forms of breast cancer.” 

https://www.nature.com/articles/s41467-025-62486-3

https://sciencemission.com/Tumor-cell-adipocyte-gap-junction