Capsaicin could activate a receptor that prevents metastasis.
A compound found in chili peppers could slow down the progression of aggressive triple negative breast cancers. This type of breast cancer is known to be particularly resistant to treatment.
Breast cancer is the most common cancer among women, with millions of diagnoses each year. While major advances have improved treatment of this disease, certain breast cancer subtypes are notoriously aggressive and more difficult to treat.
The subtypes are determined by the presence or absence of estrogen, progesterone, or the human epidermal growth factor receptor 2 (HER2). Classifying cancer by subtype allows for an easier treatment plan, because each responds differently to certain treatments.
Unfortunately, triple negative breast cancer, which is negative for all 3 receptors, is typically treated with chemotherapy since it does not respond to other treatments.
In a new study published by Breast Cancer: Targets and Therapy, investigators tested the effects of capsaicin derived from chili peppers on cultured triple negative breast cancer cells. The study was inspired by other research that suggests several transient receptor potential (TRP) channels can potentially affect cancer cells.
TRP channels are ion channels that conduct calcium and sodium ions, and can be altered by outside changes in temperature or pH, the study noted. The TRPV1 channel, an olfactory receptor, has been the source of significant research efforts recently due to its link to several diseases.
Capsaicin was previously shown to kill cancerous cells and prevent their spread in multiple types, including colon and pancreatic cancers, which makes it a good candidate for research.
In the current study, the investigators aimed to evaluate TRP channel expression in breast cancer tissues, and to understand how TRPV1 could be used to create a targeted treatment option.
The study authors discovered several olfactory receptors in cancer cells, which are proteins that bind molecules together. Interestingly, the TRPV1 receptor was found very frequently in these cells, when it is normally found in a cranial nerve.
The TRPV1 receptor was shown to be activated by capsaicin and helional, which is a compound reminiscent of the ocean. This receptor was discovered in tumor cells of 9 different patients with breast cancer, according to the study.
The researchers then added capsaicin and helional to lab cultures of the cells, which activated the TRPV1 receptors. As a result, the cells died slowly, and in larger numbers.
The investigators also reported that remaining cancer cells were not able to move quickly, which suggests that metastasis could be prevented through this method, according to the study.
However, the authors noted that consuming capsaicin would not be an effective way to treat triple negative breast cancer, but creating novel drugs that trigger this effect would likely be successful.
"If we could switch on the TRPV1 receptor with specific drugs, this might constitute a new treatment approach for this type of cancer,” concluded lead study author, Hanns Hatt, MD, PhD.