Ovarian cancer is among the most lethal gynecological cancers, as it is often detected at an advanced stage and can be resistant to treatment options. Even when therapies are initially effective, the disease can recur, posing challenges that have led scientists to search for new approaches that can slow cancer cell growth while minimizing harm to healthy cells.
A recent study published in Frontiers in Pharmacology focuses on two well-known cannabis compounds, cannabidiol (CBD) and tetrahydrocannabinol (THC). In ovarian cancer cell cultures, researchers found that when used together, the compounds reduced cancer cell growth, limited colony formation, and curbed cell migration.
While these results are preliminary and limited to laboratory settings, they provide new insight into how cannabinoids might influence the biological pathways that drive cancer.
A Need for New Options
Physicians typically treat ovarian cancer with chemotherapy, but tumors frequently develop resistance, leaving patients with limited options. Previous studies suggest cannabinoids can affect cancer cells, yet researchers still do not fully understand the biological mechanisms behind those interactions.
“Ovarian cancer remains one of the deadliest gynecological malignancies, characterized by late diagnosis, high recurrence rates, and limited effective treatment options,” said Dr. Siyao Tong of Khon Kaen University. “Our goal is to find alternative drugs that can improve efficacy and potentially reduce toxicity, ultimately bringing new hope to patients facing this challenging disease.”
Testing Cannabis Compounds in Cancer Cells
The research team tested CBD and THC on two types of ovarian cancer cells, one that responds to platinum-based drugs and another that is resistant. The scientists treated the cells with CBD alone, THC alone, and both compounds together. They also studied how healthy cells reacted to the same treatments.
Both CBD and THC slowed the growth of cancer cells when used separately. However, researchers observed the most pronounced effects when combining the two compounds. Cancer cells exposed to both compounds formed fewer, smaller colonies, suggesting reduced survival and multiplication.
“Notably, the inhibitory effect was most pronounced when CBD and THC were used in a 1:1 ratio,” Tong said.
Although neither compound alone destroyed large numbers of cancer cells, the combination was consistently more effective than either alone. This pattern suggests that CBD and THC may work through different but complementary biological pathways.
The researchers also examined whether the compounds affected the spread of cancer cells to other parts of the body. In laboratory tests, both CBD and THC reduced the ability of cancer cells to migrate, suggesting they could help slow the spread of ovarian cancer.
Restoring Balance to a Cancer-Driving Pathway
The team additionally analyzed changes in cellular signaling pathways. They focused on the PI3K/AKT/mTOR pathway, a molecular system frequently overactive in ovarian cancer and linked to tumor growth and resistance to therapy.
After the cancer cells were treated with CBD and THC, activity in this pathway shifted closer to normal levels. The researchers propose that restoring this signaling system to a balanced state could help explain why the cancer cells grew more slowly and were less mobile.
Early Findings, Clear Limits
Despite these encouraging results, the researchers stress that their work is still at an early stage. All experiments were conducted in laboratory cell cultures, so the findings may not reflect how tumors behave in the human body.
“Although our study is still preliminary, it lays an important foundation for future research into the potential applications of CBD and THC in ovarian cancer treatment,” Tong said. “By confirming their anti-cancer activity and identifying key molecular mechanisms, our findings are expected to drive further preclinical research.”
Tong also pointed out several limitations of the study, including the lack of animal experiments, clinical trials, and data on how the compounds are processed in the body. Regulatory and legal issues related to cannabinoid-based therapies also make it harder to move these findings toward practical use.