Can Marijuana Use Hasten the Progression of HPV-Positive Head/Neck Cancer?
Posted: Tuesday, January 28, 2020
The use of cannabinoids appears to promote the progression of human papillomavirus (HPV)-positive head and neck squamous cell carcinoma, and according to a study published in Clinical Cancer Research, the mechanism of this process has been identified. Researchers have discovered that tetrahydrocannabinol (THC) activates the p38 MAPK pathway in patients with HPV-positive head and neck squamous cell carcinoma, preventing apoptosis of tumor cells.
“We now have convincing scientific evidence that daily marijuana use can drive tumor growth in HPV-related head and neck cancer,” explained Joseph A. Califano, III, MD, of the University of California (UC), San Diego, in a UC San Diego press release. “Marijuana and other cannabis products are often considered benign, but it is important to note that all drugs that have benefits can also have drawbacks. This is a cautionary tale.”
Dr. Califano and colleagues studied the expression of cannabinoid receptors CNR1 and CNR2 using head and neck squamous cell carcinoma data from The Cancer Genome Atlas. They found that the expression of CNR1 and CNR2 was elevated in HPV-positive head and neck squamous cell carcinoma compared with HPV-negative disease, and knockdown of CNR1/CNR2 expression inhibited proliferation in HPV-positive cell lines. The activation of CNR1 and CNR2 in both cell lines and animal models promoted cell growth and migration as well as inhibited apoptosis through p38 MAPK pathway activation.
The researchers are now exploring whether cannabidiol has a similar effect on cancer cells as THC. In addition, they are investigating whether the p38 MAPK pathway could be a potential drug target.
Disclosure: For full disclosures of the study authors, visit aacrjournals.org.