High voltage low energy pulses promises new treatment possibilities.
Based on successful results in an experiment with a Labrador retriever using a novel treatment for glioblastoma brain cancer, the National Cancer Institute yesterday (Feb. 19) awarded Scott Verbridge, an assistant professor of biomedical engineering and mechanics at Virginia Tech , a $386,149 research grant to take a related medical procedure a step closer to using on humans.
The team’s findings from the experiment were reported in an open-access paper in the Feb. 14, 2011, issue of the Journal of Technology Cancer Research and Treatment.
Since the surgery, the investigators have continued experiments and mathematical modeling techniques that are leading toward effective treatments for humans with glioblastoma, the most common and deadly malignant brain tumor.
Punching holes in a tumor
The technique, invented by Virginia Tech faculty member Rafael Davalos, is called irreversible electroporation (basically, punching tiny holes in cancer tissue with electricity).
The investigators propose in the current project that these pulses can be tuned “to target the unique physical properties of malignant cells,” Verbridge said.
By contrast, chemotherapy and radiation used to reduce or eliminate cancerous cells are not discriminatory and can also affect healthy cells.
Clinical trials using the irreversible electroporation procedure have also been conducted for treatment of liver, kidney, pancreatic, and lung cancer.
“The procedure is essentially done with two minimally invasive electrodes placed into the targeted region, delivering approximately 80 pulses to the site in about one minute. The pulses are high voltage but low energy, so no significant heating occurs as a result of the procedure,” Davalos said. They use a device called Nanoknife for that purpose.
Pulse duration is significant in this process. Earlier studies have demonstrated that length of the pulse accounts for the dead cell lesion size, and the current work will explore the impact of varying these time parameters on the response of different cell types within gliomas.
In addition to researching the response of cell lines, experiments also will include patient-derived cells harvested by colleagues at Wake Forest University and The Ohio State University Comprehensive Cancer Centers. The researchers plan to build three-dimensional in vitro tumors using these patient-derived cells.
They then will characterize the response of the most highly aggressive tumor cell populations, in physiologically relevant tissue models, to these electric field therapies. Using live staining techniques and confocal microscopy, the researchers will be able to measure real-time responses of the cells to the irreversible electroporation.
“We believe our studies will provide a significant advancement in our understanding of glioma biology and point to new treatment possibilities,” said Verbridge, who conducted postdoctoral research at the National Institutes of Health (NIH)-funded Cornell University Physical Sciences in Oncology Center. Verbridge also is a principal investigator on an additional NIH-funded project investigating glioma transcriptional dynamics, in collaboration with Chang Lu of Virginia Tech’s Department of Chemical Engineering.