In a study at the University of North Carolina Lineberger Comprehensive Cancer Center, researchers have found that cancer cells grow more quickly when they are placed into fatty, obese tissue.
The team of researchers studied a type of breast cancer, that is known as triple-negative breast cancer. They transplanted cancer from lean laboratory models into the models of obese, lean and formerly obese microenvironments to see how the tumors would react.
“We’re interested in something called the ‘microenvironment,’ which is basically cells around the tumor and the chemicals those cells produce,” Liza Makowski, a UNC Lineberger member and associate professor in the UNC Gillings School of Global Public Health, said in a press release. “In breast cancer, we know that the cancer is embedded in very fatty tissue because the breast is made up largely of adipose tissue. As a person becomes obese, that can change the adipose tissue, or change this microenvironment where the cancer can start or progress.”
Researchers found that the tumors grew significantly larger in the obese models than in the lean models, and were also larger than tumors in models that were formerly obese, suggesting that weight loss could correct changes to the microenvironment that were helping drive the cancer.
Interestingly, the gene expression patterns within the tumors themselves produced only subtle changes.
“Where we saw the most changes were in the mammary glands around the tumors,” said Alyssa J. Cozzo, a graduate student at UNC Gillings. “This implies that the microenvironment surrounding the tumor can be a driver of tumor growth, even when the tumor cells and the other cells that make up the tumor itself are relatively small.”
The findings may have important implications for understanding the link between obesity and cancer.
The study will be presented at the American Association of Cancer Research Annual Meeting 2017 on April 3.