Triple Negative Breast Cancer (TNBC) is a difficult type of cancer to treat because it is negative for progesterone, estrogen, and HER-2 receptors. Because TNBC is negative for these three receptors, it does not respond to normal hormonal therapies. The purpose of my experiment is to see if different cannabinoids, compounds from the cannabis plants, could be used as alternative treatment options. These experiments employed three different cannabinoids: ajulemic acid, cannabidiol, and hemp oil. Cell viability was measured after 72 hours of treatment using a MTT assay. The results showed that the three cannabinoids could be used to effectively destroy the TNBC cells. We used this data to calculate the median lethal dose (LD-50), the concentration of the cannabinoid that can be given to destroy half of the cells. Our data suggest, cannabinoids could potentially be used as an alternative treatment for TNBC. However, much more testing would need to be done before it could be confirmed as a viable treatment option.
It’s no secret that many cancer patients are using cannabis to help manage pain, fatigue, nausea, and other side effects of chemotherapy. Less well known is the fact that extensive preclinical research shows that plant cannabinoids — most notably, tetrahydrocannabinol ( THC ) and cannabidiol ( CBD ) – produce antitumor responses in various animal models of cancer.
Two biomarkers frequently used to diagnose breast cancer are hormonal receptors (the estrogen receptor and progesterone receptor) and the HER2 oncogene (a gene which can transform a normal cell into a tumor cell). But a more aggressive malignancy, known as “triple-negative breast cancer,” doesn’t express hormonal receptors or the HER2 oncogene. No targeted therapy exists for triple-negative breast cancer, so patients are treated with harsh chemotherapies that indiscriminately kill proliferating cells, whether cancerous or not.
Tricky to Treat
It is estimated that one in eight women will develop breast cancer. Breast cancer is tricky to treat because there are few biomarkers that signal when someone has the disease, and many patients show or develop resistance to current therapies. Moreover, several specific types of breast cancer respond poorly to modern treatment. These difficulties underscore the importance of exploring new treatments for breast cancer.
The Spanish scientists emphasize that the whole plant cannabis drug preparation “did not, in any case, diminish the antitumor efficacy of any of the standard treatments.” That’s good news for cancer patients who use cannabis to manage the adverse side effects of chemo. Cannabis is very likely a safe add-on therapy for treating pain and nausea and for appetite stimulation. And it may also increase the efficacy of standard chemotherapy treatments, which means that chemo could be more effective – requiring lower and less toxic doses – when used in combination with cannabis.
Triple-negative, the breast cancer subtype with the worst prognosis, does not generally respond well to chemotherapy. But the Spanish group found that THC and THC -rich cannabis oil both offer some hope in improving treatment outcomes for this highly aggressive cancer. Again, the whole plant extract was found to be more effective than THC alone in decreasing the viability of cancer cells in vitro as well as in mouse model studies.