Obesity is related to a variety of health problems, but its connection to cancer may not be as well known. Yet, researchers know that being overweight or obese increases the risk of a number of cancers, including breast cancer, and people who are obese are more likely to have aggressive forms of the disease. But researchers haven’t had a good understanding of the reasons behind these observations.
A research team from Germany recently published a study that may explain the biological mechanisms at work that increase aggressiveness in breast cancer. With a better understanding of what is happening at the molecular level, researchers can start to develop new treatments.
Complex cell processes contribute to cancer spread
Every cell has a complex network of biological processes that need to function properly in order for a cell to grow and survive. Cancer cells are no exception, though their processes are often different from healthy cells.
One such process is the creation of fatty acids, which are essential building blocks for the cell’s structure. In order to create fatty acids, the cells needs a protein called ACC1. The ACC1 protein does not work properly in cancer cells, starting a chain reaction that increases the cell’s aggressiveness and ability to spread. As a result, prompting the ACC1 protein to work properly again could be an effective way to stop breast cancer from spreading.
Proteins related to obesity may increase cancer spread
The research team studied the ACC1 protein and its activity to look for potential vulnerabilities. They identified that 2 proteins, called leptin and TGF-B, could prevent ACC1 activity, thereby contributing to cancer spread. Importantly, these proteins are found at higher levels in people who are severely overweight, which helps to explain why breast cancer is often more aggressive in people who are obese.
The researchers were particularly interested in the leptin protein. They lowered the amount of leptin levels to which cancer cells were exposed, which resulted in ACC1 functioning properly and reduced the cancer cells’ ability to spread. In addition, the researchers identified an immune system protein called an antibody that could lower leptin levels and could have potential as a breast cancer treatment.
The researchers also looked at the molecules involved in the ACC1 protein’s chain reaction that can increase breast cancer spread. Interestingly, they found that this same process is also at work in lung cancer cells.
Same biological processes may be involved in many cancers
This research helps to explain why people who are obese are more likely to have aggressive forms of the disease. Proteins that are associated with obesity trigger complex biological pathways involved in cancer spread, but they may also be targets for new treatments.
An important aspect of this research is the potential that it may apply to many forms of cancer. The biological process of building fatty acids, and the role of ACC1 in this process, is critical to cell functioning, and it is likely that this process could be at work in many forms of cancer. It may be possible to improve treatment for many forms of cancer by tackling this one essential biological process.
Eileen Hoftyzer, BSc, and Carolyn Goard, PhD