Most breast cancer patients die not as a result of lesions localized in this organ, but as a result of metastases, e.g. to the lungs, brain, bones. Researchers from the Cancer Research UK Cambridge Institute have discovered what determines the ability of cancer cells to spread throughout the body of a patient.
Asparagine – one of the protein-building amino acids – plays an important role in the formation of tumor metastasis, and limiting the production of this compound by the body and its supply may be a way to inhibit the spread of breast cancer cells, the authors of the study showed using a mouse model.
The researchers ‘silenced’ the asparagine synthetase (ASNS) gene in rodents with breast cancer with a drug called L-asparaginase (which is used to treat acute lymphoblastic leukemia). The production of this amino acid in animals significantly decreased. At the same time, its supply with food was limited. It turned out that cancer cells had stopped “settling” in other organs.
Scientists also analyzed samples of biological material from human cancer patients. It turned out that the greater the ability of a cancer cell to produce asparagine, the more easily it metastasized. Not only for breast cancer – also for others, including kidney cancer and head and neck cancer.
– We identified one of the key mechanisms that give breast cancer cells the ability to spread, says Prof. Greg Hannon, lead author. – When asparagine availability is decreased, the ability of cancer cells to spread to other organs decreases, although the availability of this amino acid does not affect the primary tumor. Limiting the supply and production of asparagine – whether through diet or otherwise – may become an additional element in the treatment of certain cancers in the future, explains Prof. Hannon.
Foods rich in aspartic acid include dairy, beef, poultry, eggs, fish, seafood, potatoes, asparagus, legumes, nuts, soybeans, and whole grains. In turn, a low asparagine content is found in most vegetables and fruits.
However, there is currently no evidence that restricting consumption of these foods can help fight cancer, so it’s important that cancer patients talk to their doctor before making any dietary modifications, warns Martin Ledwick of Cancer Research UK.