A new preclinical study published in Frontiers in Immunology finds that cannabidiol (CBD) may help slow the growth of HPV-positive head and neck squamous cell carcinoma (HNSCC) by activating the immune system and disrupting cancer cell growth.
Researchers at the University of California San Diego found that CBD significantly reduced tumor growth in mice with competent immune systems, but not in immune-deficient mice, suggesting its anti-cancer effects are driven by immune mechanisms. Treated mice showed increased infiltration of key immune cells—including CD4+ and CD8+ T cells, B cells, and natural killer cells—into the tumors.
In cell studies, CBD promoted apoptosis and suppressed proliferation and migration of HPV-positive cancer cells by activating the MAPK signaling pathway, including ERK1/2, JNK, and p38 MAPK markers. The presence of these markers was also observed to co-localize with T cells in tumor tissue, further suggesting an immune-modulating mechanism.
Depleting CD4+ T cells in mice negated CBD’s anti-tumor effects, highlighting their essential role in mediating the compound’s therapeutic potential. Interestingly, this effect was not seen when CD8+ T cells were removed.
While prior research linked THC to possible cancer-promoting effects in similar cancers, this study underscores the contrasting impact of CBD, which may enhance immune coordination and support anti-tumor responses.
“In conclusion,” the researchers state, “our study suggests that CBD inhibits tumor cell proliferation in HPV-positive HNSCC by activating MAPK pathway and exhibits anti-tumor activity by modulating the CD4+T and CD8+T cells in the tumor immune microenvironment… specific cannabinoids may become an integral component of comprehensive cancer treatment regimens, offering new hope to patients with HPV-positive head and neck cancer.”
Researchers emphasize that further clinical investigation is needed to determine how CBD might be integrated with chemotherapy, immunotherapy, or radiation in cancer treatment strategies.
