An Israeli study has eliminated glioblastoma, the most deadly brain tumors, in mice by identifying and destroying their “power source.”
The Tel Aviv University scientists behind the peer-reviewed research are now working on identifying drugs to replicate the effect in humans. They hope to find an existing drug that may work and then repurpose it, which they say could happen within two years if things go smoothly.
The method is basically to “starve” glioblastoma tumors by removing their source of energy, said brain immunologist Dr. Lior Mayo, the lead author of the study.
He told The Times of Israel that normally, scientists try to attack tumors directly, for example with chemotherapy. “Instead, we decided to ask if there’s anything we can change in the tumor’s environment that could harm it,” he explained.
Astrocytes are brain cells that are so called because they look like stars. Glioblastoma tumors shifts the surrounding astrocytes to an unusually active state. Mayo, and his PhD students Adi Tessler and Rita Perelroizen, wanted to know what the astrocytes do in relation to the tumor.
Using genetic modification, he could produce mice with glioblastoma tumors, and then remove all astrocytes from around the tumor. “We found that when we did this, the tumors vanished and stayed away for as long as we repressed the astrocytes,” he said.
“In fact, even when we stopped suppressing the astrocytes, some 85 percent of the mice stayed in remission. However, among the control group, in which all astrocytes remained, all mice died.”
In the study, published in the journal Brain, the scientists suggest “that targeting astrocyte immunometabolic signaling may be useful in treating this uniformly lethal brain tumor.”
The research concluded that astrocytes help tumors in two main ways. Firstly, they hijack immune cells that normally protect the body so they help tumors. The astrocytes do this by secreting proteins to tumors that change their behavior.
Secondly, the astrocytes turn cholesterol from the body into an energy source for tumors. It was already known brain tumors receive energy that originates from cholesterol, but the specifics of how and where this happens were not understood.
Mayo said: “We found that astrocytes supply energy needed for the growth of the tumor, by secreting cholesterol. They synthesize the cholesterol into energy and send it to the tumor cells, which then use it as an energy source.”
He said that his lab’s efforts are now focused on trying to transform the breakthrough in to a treatment for humans. “We’re optimistic,” he said. “If we can repurpose an existing drug, as we hope, it could take around two years, but if an original drug is needed it would take longer.”