Ovarian cancer remains a “big killer” among female gynecologic cancers, marked by diagnostic and therapeutic challenges, a high risk of recurrence, and a substantial mortality rate. Preliminary evidence from a recent study in Frontiers in Pharmacology highlights the antitumor effects of CBD (cannabidiol) and THC (delta-9-tetrahydrocannabinol) on ovarian cancer cells.
The Research Effort
Limited treatment options, often rendered ineffective by late-stage disease—and in some cases already metastatic—are the main challenges pushing researchers to explore and identify potential alternative medicines capable of improving the curability of ovarian cancer and reducing the toxicity of current therapies, thereby expanding the arsenal of options available to patients facing this difficult cancer.
Despite progress in therapeutic strategies, the drugs currently available still present significant side effects. The research focus is now turning to the potential use of two cannabis derivatives: CBD (cannabidiol) and THC (delta-9-tetrahydrocannabinol), which have demonstrated therapeutic potential in the treatment of other tumors. Based on this evidence, a group of Chinese and Thai researchers has initiated a study to test their effectiveness against ovarian cancer cells as well, and the investigations conducted thus far show promising initial antitumor effects. Specifically, the researchers examined two distinct ovarian cancer cell lines, one sensitive to platinum-based drugs and one resistant to this treatment, exposing them to CBD, THC or both.
The objective was to determine whether cancerous cells could survive and replicate after exposure. In parallel, the researchers also stimulated a healthy cell line to verify whether the compounds could cause specific damage. The experiments revealed that cells from both tumor lines treated with CBD or THC formed colonies that were fewer in number and smaller in size. Although both compounds impeded the replication of cancer cells, it was their combination that produced particularly strong results.
Thus the hypothesis is that THC and CBD act on cancer cells in different ways and that, in synergy, they can amplify their therapeutic potential: it was observed, in fact, that the most pronounced inhibitory effect was achieved using CBD and THC in a 1:1 ratio. The study shows that the compounds prevent cellular migration, thereby holding potential to stop the spread of ovarian cancer to other parts of the body, noting that metastasis is a major contributor to mortality. Moreover, since both cell lines were affected similarly, one could infer the compounds might be effective against other forms of ovarian cancer as well. Finally, on tests conducted with healthy cells, the compounds and their combinations showed minimal effects on these cells, suggesting a potentially lower toxicity of these treatments, albeit still perceived as such by patients and more tolerable than current drugs.
The Signaling Pathways Explored
To understand the mechanism behind these antitumor effects, scientists examined cellular signaling pathways, noting for example that the PI3K/AKT/mTOR pathway is hyperactivated in ovarian cancer cells, which would contribute to tumor development and treatment resistance.
CBD and THC compounds appeared to restore normal regulation of the pathway, explaining why cancer cells could not reproduce and began to die after treatment. While these data are intriguing, they will require further research to translate these early findings into drugs that can be administered to patients. Moreover, if future studies confirm these effects, a CBD-THC combination therapy could become a strategy for developing new therapeutic options.
However, several limitations of the study should be noted: all experiments were conducted in vitro, so the results might not fully reflect the complexity of tumor behavior in living organisms, given that in vivo models and pharmacokinetic data are crucial to determine whether CBD/THC could be used clinically in a safe and effective manner. Finally, regulatory and legal issues surrounding cannabinoid therapy could also influence future translational research.
Study
Tong S, Loilome W, Namwat M et al. Selective anti-cancer effects of cannabidiol and Δ9-tetrahydrocannabinol via PI3K/AKT/mTOR inhibition and PTEN restoration in ovarian cancer cells. Frontiers in Pharmacology, 2025, Volume 16 | Doi: https://doi.org/10.3389/fphar.2025.1693129
Abbonati a Karla Miller
