Currently, only 5 percent of patients with GBM survive longer than three years, and the average life expectancy of a patient is 15 months. Even when aggressive therapies are implemented, "GBM is essentially incurable," the researchers wrote in the study. So identifying vulnerabilities in this cancer's cells is an essential step in the development of new drug therapies.
The compound that eventually caught researchers' attention is called "Vacquinol-1," and although it certainly did kill cancer cells, it did so in a way that was unlike anything else they'd seen.
The molecule works by shutting off the cells' ability to control what gets in and out of their walls. This causes bag-like vessels filled with water and other materials, called vacuoles, to accumulate in the cells. Under these conditions, the cells eventually reach capacity and explode. But what's truly remarkable is that the noncancerous cell types that surround the cancer cells remain intact, so the treatment is actually GBM-specific.
Treatments that work in a petri dish, however, don't always work in the living. So the scientists set up a second test involving mice, and fed the compound to a group of mice with brain tumors for five days. The treatment did not cause any severe side effects. Instead, the tumors stopped growing and eventually disappeared. Moreover, six of the eight mice who received the treatment survived for 80 days following the feeding period — about 50 days longer than the mice who weren't given the drug.
Ravi Bellamkonda, a neuroscientist at the Georgia Institute of Technology who did not participate in the study, wrote in an email to The Verge that he was intrigued by the idea of being able to induce death in glioma cells specifically. "They have shown very exciting results."
But Bellamkonda also expressed some reservations about the approach, because the study's researchers had to administer what he calls "relatively high levels of the drug" to make it work. Furthermore, it's unclear if the concentrations of the drug need to be higher elsewhere in the body to reach the cancer cells — which might induce side-effects that would have been difficult to identify in the study. "This said, enhancing survival by several fold in aggressive tumor models is encouraging," he wrote. "I'd love to see more studies."
- Reference: Cell