Electrical zapping of brain cells hints at a sweet spot for tumor death
The brain’s natural defenses can make tumors in this part of the body difficult to treat, but scientists have found some early success using electrical fields in laboratory models. The technique involves using electrical energy to selectively target cancer cells while leaving healthy cells unharmed, with the scientists also demonstrating how it could be used to open up the blood-brain barrier for more effective chemotherapy.
The work was carried out by researchers at the University of Saskatchewan and looks to leverage technology used to treat cancers elsewhere in the body through electrical currents. One of these, known as NanoKnife Irreversible electroporation (IRE), has been commercially available for treatment of soft tissue tumors in the lung, prostate, pancreas and other hard-to-reach locations since 2009. The other, high-frequency irreversible electroporation (H-FIRE), has also shown promise in laboratory models.
Both are designed to trigger death in targeted cells by using very short electrical pulses to destabilize the cellular membranes, via electrodes inserted into a tumor. In the context of brain cancer, this could mean inserting long needles through the skull for targeted treatment of a tumor.
“A safer and more effective cancer treatment may be clinically possible,” said co-author of the study Dr Mike Moser. “Patients with brain tumors may now have another option for local treatment that does not involve opening the skull, and does not involve heat or radiation.”
Such treatments are still a fair way down the track, but Moser and his team have taken some promising early steps. The study involved three types of brain cells: one brain cancer cell line and two healthy cell lines from the blood-brain barrier, the nearly-impermeable membrane that protects the brain from harmful pathogens in the blood and allows only small molecules to pass.
The team experimented with electrical fields of varying strengths, and assessed the viability of the different cells thereafter. This revealed that the lethal threshold for the brain cancer cells was significantly lower than the healthy cells, which bodes well for selectively targeting them to treat tumors. But the scientists also found the technique could be used to temporarily disrupt the blood-brain barrier cells and open the barrier for drug delivery.
This could lead to some useful avenues for drug treatment of brain cancer, where the blood-brain barrier has historically proven a difficult roadblock to overcome. We have previously seen scientists find success using ultrasound to disrupt the barrier so chemotherapy drugs can pass through, while special nanoparticles might also play a role. Though only demonstrated on cells in the lab, this new research could one day see another approach added to scientists’ toolkit.
“The blood-brain barrier prevents many treatment drugs from getting to the tumor,” said Dr. Chris Zhang (PhD), co-author on the study. “We’ve shown that our technique can also help to open this barrier, so the brain is better able to receive other treatments – like chemotherapy or drugs that help increase the immune response – and help the patient fight the tumor in a systematic manner.”
The research was published in the Journal of Biomechanical Engineering.
Source: University of Saskatchewan