Researchers identified a fatty acid that may help the body destroy damaged or cancerous breast cells.
Fat cells in lean breast tissue produced more of this fatty acid than fat cells in obese tissue.
The discovery could eventually lead to new approaches for restoring this natural protection, but more research is needed.
Obesity has been linked with breast cancer risk, but researchers are still working to understand exactly why.
Now, scientists at Huntsman Cancer Institute at the University of Utah have identified a potential piece of the puzzle: Obesity may cause the body to lose some of the natural protection that helps eliminate cancerous cells.
The researchers focused on fat cells in breast tissue, which are also known as adipocytes. According to the researchers, these cells can behave differently depending on whether they come from lean or obese tissue.
Their findings suggest that fat cells in lean breast tissue produce higher amounts of a fatty acid called 9S-HODE. This substance appears to help trigger a type of cell death called ferroptosis, which can eliminate damaged or potentially cancerous cells.
“We uncovered the role of a molecule that normally appears in lean tissue that restrains breast cancer growth but is less present with obesity,” researcher Keren Hilgendorf, Ph.D., Huntsman Cancer Institute investigator, assistant professor of biochemistry at the U, and senior author of the study, said in a news release.
“We know obesity is often a driver of breast cancer, and researchers in our field usually consider how obesity is promoting the disease. But we hadn’t really considered that obesity could also be the loss of something that naturally protects us.”
How the study worked
The researchers used preclinical models to investigate the differences between lean and obese breast tissue. Their work included studying breast tissue from donors as well as mouse models. They compared fat cells from lean and obese tissue and looked at the substances those cells produced.
One important difference was the amount of 9S-HODE produced by the fat cells. The researchers found that lean fat cells produced much more of the fatty acid than obese fat cells.
They then increased the amount of 9S-HODE in obese fat cells in mouse models to see what effect it had on breast cancer growth.
What the results could mean for consumers
The researchers found that increasing 9S-HODE in obese fat cells suppressed breast cancer tumor growth in their mouse models. The findings suggest that when obesity changes breast fat cells, those cells may produce less of a substance that helps cancerous cells die.
That doesn't mean obesity is the only factor involved in breast cancer, or that everyone with obesity will develop the disease. The researchers specifically note that breast cancer can develop for many reasons.
Still, the discovery could point toward a new treatment strategy. Because 9S-HODE is naturally produced by the body, researchers are interested in whether restoring or increasing it could eventually help restore some of the body's natural protection against breast cancer.
For now, however, this remains an early research finding. The researchers describe it as one discovery that could open the door to further studies rather than an available treatment.
“We believe this shift in the understanding of the roles of lean and obese adipocytes is the start of something. This is just one discovery, and it’s not the end of the road,” first author Meghan Curtin, doctoral candidate in molecular biology at the U, said in the release.
“This opened our eyes to new ways to think about science, and hopefully we can harness what our bodies are already doing to make progress against this disease.”