An existing antidepressant, vortioxetine, has shown promise in preclinical studies as a potential treatment for glioblastoma, an aggressive and currently incurable brain tumor. Researchers at ETH Zurich and the University Hospital Zurich (USZ) have found that vortioxetine, already approved for treating depression, can cross the blood-brain barrier and effectively suppress glioblastoma cell growth in cell cultures and mice. These findings, published in Nature Medicine, suggest that vortioxetine could be a valuable addition to existing glioblastoma treatment regimens. Glioblastoma is a particularly aggressive brain tumor, with a median survival time of approximately 15 months. Current treatments, including surgery, radiation, and chemotherapy, offer limited success, and new therapeutic strategies are urgently needed.
Identifying Potential Treatments
The research team, led by Professor Berend Snijder from ETH Zurich, utilized a high-throughput screening platform called pharmacoscopy to test the effects of various neuroactive substances on glioblastoma cells. This platform allows for the simultaneous testing of hundreds of active substances on living cells from human cancer tissue. The study focused on neuroactive substances known to cross the blood-brain barrier, including antidepressants, Parkinson’s medications, and antipsychotics. In total, 130 different agents were tested on tumor tissue from 40 patients.
Sohyon Lee, PhD, the lead author of the study, analyzed cancer tissue from patients who had recently undergone surgery at USZ. The researchers used imaging techniques and computer analysis to determine which substances had an effect on the cancer cells. The results indicated that some antidepressants, including vortioxetine, were unexpectedly effective against the tumor cells. Vortioxetine was found to trigger a signaling cascade that suppresses cell division, a key mechanism in cancer growth.
Mechanism of Action and In Vivo Studies
Further investigation using computer models revealed that the joint signaling cascade of neurons and cancer cells plays a crucial role in the effectiveness of neuroactive drugs against glioblastoma. This insight explains why some neuroactive drugs work while others do not. To validate these findings, the researchers tested vortioxetine on mice with glioblastoma. The drug demonstrated good efficacy, especially when combined with the current standard treatment of surgery, chemotherapy, and radiation. In one experiment, mice treated with vortioxetine showed 20-30% higher survival rates compared to those treated with chemotherapy alone.
Clinical Trials and Future Directions
The research team is now preparing for two clinical trials to evaluate the efficacy of vortioxetine in human glioblastoma patients. In one trial, patients will be treated with vortioxetine in addition to standard treatment. In the other, patients will receive a personalized drug selection based on the pharmacoscopy platform. Michael Weller, MD, professor at the University Hospital Zurich, emphasized the potential benefits of vortioxetine, stating, "The advantage of vortioxetine is that it is safe and very cost-effective. As the drug has already been approved, it doesn’t have to undergo a complex approval procedure and could soon supplement the standard therapy for this deadly brain tumor."
Cautions and Considerations
Despite the promising results, the researchers caution against self-medication with vortioxetine. "We don’t yet know whether the drug works in humans and what dose is required to combat the tumor, which is why clinical trials are necessary. Self-medicating would be an incalculable risk," Weller warned. Snijder added, "So far, it’s only been proven effective in cell cultures and in mice."
If vortioxetine proves effective in clinical trials, it would be the first time in recent decades that an active substance has been found to improve the treatment of glioblastoma. The researchers believe that this study represents a significant step forward in the search for better treatments for this devastating disease. As Snijder concluded, "We started with this terrible tumor and found existing drugs that fight against it. We show how and why they work, and soon we’ll be able to test them on patients."
