Brain biopsy is the removal of a small piece of brain tissue for the diagnosis of abnormalities of the brain, a complicated and invasive surgical process. Now, scientists at the Washington University in St. Louis discovered a way to easily detect tumor biomarkers through a simple blood test.
The technique allows biomarkers from a cerebrum tumor to go through the intense blood-brain barrier into a patient’s blood utilizing noninvasive centered ultrasound and some modest air pockets, conceivably disposing of the requirement for a surgical biopsy.
The blood test would reveal the amount of mRNA in the blood, which gives physicians specific information about the tumor that can help with diagnosis and treatment options.
Chen, assistant professor of biomedical engineering in the School of Engineering & Applied Science and of radiation oncology in the School of Medicine, said, “While researchers have already learned how to get a drug through the blood-brain barrier into the brain via the bloodstream, no one — until now — has found a way to release tumor-specific biomarkers — in this case, messenger RNA (mRNA)— from the brain into the blood.”
“I see a clear path for the clinical translation of this technique. Blood-based liquid biopsies have been used in other cancers but not in the brain. Our proposed technique may make it possible to perform a blood test for brain cancer patients.”
Scientists experimented on mice using two different types of the deadly glioblastoma brain tumor. They focused on the tumor utilizing centered ultrasound, a strategy that utilizes ultrasonic vitality to target tissue somewhere down in the body without entry points or radiation. Like an amplifying glass that can center daylight to a small point, centered ultrasound concentrates ultrasound vitality to a minor point profound into the cerebrum.
When they had the objective — for this situation, the mind tumor — specialists at that point infused microbubbles that moved through the blood like red platelets. At the point when the microbubbles achieved the objective, they popped, causing minor breaks of the blood-mind obstruction that permits the biomarkers from the cerebrum tumor to go through the hindrance and discharge into the circulatory system. A blood test can decide the biomarkers in the tumor.
Eric C. Leuthardt, MD, a neurosurgeon, said, “In many ways, this has been a holy grail for brain tumor therapy. Having the ability to monitor the changing molecular events of the tumor in an ongoing way allows us to not only better diagnose a tumor in the brain, but to follow its response to different types of treatment.”
Chen said, “Once the blood-brain barrier is open, physicians can deliver drugs to the brain tumor. Physicians can also collect the blood and detect the expression level of biomarkers in the patient. It enables them to perform molecular characterizations of the brain tumor from a blood draw and guide the choice of treatment for individual patients.”
“This noninvasive focused ultrasound-enabled liquid biopsy technique can be useful for long-term monitoring of brain cancer treatment response, where repeated surgical tissue biopsies may not be feasible. Meanwhile, variations within tumors pose a significant challenge to cancer biomarker research. Focused ultrasound can precisely target different locations of the tumor, thereby causing biomarkers to be released in a spatially-localized manner and allow us to better understand the spatial variations of the tumor and develop better treatment.”
Now, scientists are planning to use the technique with immunotherapy. This will offer precision treatment that targets specific biomarkers in the brain. They are continuing to work to refine the process. The future will require integration with advanced genomic sequencing and bioinformatics to enable even more refined diagnostics. These efforts are being led by co-authors Allegra Petti, assistant professor of medicine, and Xiaowei Wang, associate professor of radiation oncology.
The results of the study are published in Scientific Reports April 26, 2018.