In culinary preparation, mirepoix is often used as the basis for a multitude of dishes. Now, a molecule that resides in one of the members of this foundational trinity—traditionally consisting of celery, carrots, and onions—could potentially improve the treatment of the devastating trinity, triple-negative breast cancer. Investigators at the University of Missouri (MU) found that a flavonoid molecule named luteolin, a natural compound found in vegetables such as celery and broccoli, as well as herbs such as thyme and parsley, could reduce the risk of developing metastasis originating from triple-negative breast cancer.
“Triple-negative breast cancers are cancer cells that lack three receptors targeted by current chemotherapy regimens,” explained senior study investigator Salman Hyder, Ph.D., professor of biomedical sciences in the College of Veterinary Medicine and the Dalton Cardiovascular Research Center at MU. “Because of this lack of receptors, common cancer drugs can't 'find' the cells, and doctors must treat the cancer with extremely aggressive and highly toxic treatment strategies. Women with this type of breast cancer also frequently develop metastatic lesions that originate from drug-resistant cells. Therefore, safer therapeutic therapies that are more effective are being sought for this deadly type of cancer in women.”
More than 100 women die from breast cancer every day in the United States. Triple-negative breast cancers, which comprise 15% to 20% of all breast tumors, are a particularly deadly form of the disease that often metastasizes to distant sites. Dr. Hyder and his team focused on luteolin, which is not only a naturally occurring plant compound, but previous work has shown it also to be nontoxic and effective at inhibiting growth in several types of cancer.
Using human triple-negative breast cancer cells grown in mice, the researchers tested luteolin to determine if it could suppress metastasis. In the first series of tests, the investigators found that luteolin inhibited the metastasis of triple-negative cancer in the lungs of affected mice.
“Mice exposed to human triple-negative breast cancer cells experienced significantly reduced metastatic growth in their lungs after being treated with luteolin,” Dr. Hyder noted. “In almost every case, the mice also saw no weight loss, which means luteolin has no toxic effects—this plant compound is both safe and effective.”
The findings from this study were published recently in Breast Cancer: Targets and Therapy in an article entitled “Luteolin Inhibits Lung Metastasis, Cell Migration, and Viability of Triple-Negative Breast Cancer Cells.”
The MU team further tested luteolin and its effects on subduing the migration of triple-negative breast cancer cells throughout the body. The scientists found that in vitro-cultured triple-negative cells that were treated with luteolin were inhibited by the plant compound from migrating.
Triple-negative breast cancer cells are highly mobile in the body, which helps them metastasize to other organs throughout the body,” Dr. Hyder remarked. “We found that luteolin inhibits that migration and also can kill cancer cells. We contend that these studies support further investigation of luteolin as an antimetastatic agent that could be used to combat triple-negative breast cancer and its metastasis.”
While the researchers were excited by their initial results, they cautioned against over analysis of the data, as additional studies are needed to determine the effect of the compound in humans. However, if additional studies are successful within the next few years, MU officials will request authority from the federal government to begin human drug development (this is commonly referred to as IND, or Investigative New Drug, status). After this status has been granted, researchers may conduct human clinical trials with the hope of developing new treatments for triple-negative breast cancer in women.