MicroRNAs in urine could prove to be promising biomarkers in clinical laboratory tests designed to diagnose brain tumors regardless of the tumor’s size or malignancy, paving the way for early detection and treatment
Researchers at Nagoya University in Japan have developed a liquid biopsy test for brain cancer screening that, they claim, can identify brain tumors in patients with 100% sensitivity and 97% specificity, regardless of the tumor’s size or malignancy. Pathologists will be interested to learn that the research team developing this technology says it is simple and inexpensive enough to make it feasible for use in mass screening for brain tumors.
Neurologists, anatomic pathologists, and histopathologists know that brain tumors are one of the most challenging cancers to diagnose. This is partly due to the invasive nature of biopsying tissue in the brain. It’s also because—until recently—clinical laboratory tests based on liquid blood or urine biopsies were in the earliest stages of study and research and are still in development.
Thus, a non-invasive urine test with this level of accuracy that achieves clinical status would be a boon for the diagnosis of brain cancer.
Researchers at Japan’s Nagoya University believe they have developed just such a liquid biopsy test. In a recent study, they showed that microRNAs (tiny molecules of nucleic acid) in urine could be a promising biomarker for diagnosing brain tumors. Their novel microRNA-based liquid biopsy correctly identified 100% of patients with brain tumors.
The Nagoya University scientists published their findings in the journal ACS Applied Materials and Interfaces, titled, “Urinary MicroRNA-based Diagnostic Model for Central Nervous System Tumors Using Nanowire Scaffolds.”
Well-fitted for Mass Screenings of Brain Cancer Patients
According to the National Cancer Institute (NCI), brain and other central nervous system (CNS) cancers represent 1.3% of all new cancer cases and have a five-year survival rate of only 32.6%.
In their published study, the Nagoya University scientists wrote, “There are no accurate mass screening methods for early detection of central nervous system (CNS) tumors. Recently, liquid biopsy has received a lot of attention for less-invasive cancer screening. Unlike other cancers, CNS tumors require efforts to find biomarkers due to the blood–brain barrier, which restricts molecular exchange between the parenchyma and blood.
“Additionally, because a satisfactory way to collect urinary biomarkers is lacking, urine-based liquid biopsy has not been fully investigated despite the fact that it has some advantages compared to blood or cerebrospinal fluid-based biopsy.
“Here, we have developed a mass-producible and sterilizable nanowire-based device that can extract urinary microRNAs efficiently. … Our findings demonstrate that urinary microRNAs extracted with the nanowire device offer a well-fitted strategy for mass screening of CNS tumors.”
The Nagoya University researchers focused on microRNA in urine as a biomarker for brain tumors because “urine can be collected easily without putting a burden on the human body,” said Atsushi Natsume, MD, PhD, Associate Professor in the Department of Neurosurgery at Nagoya University and a corresponding author of the study, in a news release.
A total of 119 urine and tumor samples were collected from patients admitted to 14 hospitals in Japan with CNS cancers between March 2017 and July 2020. The researchers used 100 urine samples from people without cancer to serve as a control for their test.
To extract the microRNA from the urine and acquire gene expression profiles, the research team designed an assembly-type microfluidic nanowire device using nanowire scaffolds containing 100 million zinc oxide nanowires. According to the scientists, the device can be sterilized and mass-produced, making it suitable for medical use. The instrument can extract a significantly greater variety and quantity of microRNAs from only a milliliter of urine compared to traditional methods, such as ultracentrifugation, the news release explained.
Simple Liquid-biopsy Test Could Save Thousands of Lives Each Year
While further studies and clinical trials will be necessary to affirm the noninvasive test’s accuracy, the Nagoya University researchers believe that, with the inclusion of additional technologies, a urine-based microRNA test could become a reliable biomarker for detecting brain tumors.
“In the future, by a combination of artificial intelligence and telemedicine, people will be able to know the presence of cancer, whereas doctors will be able to know the status of cancer patients just with a small amount of their daily urine,” Natsume said in the news release.
Biomarkers found in urine or blood samples that provide clinical laboratories with a simple, non-invasive procedure for early diagnosis of brain tumors could greatly increase the five-year survival rate for thousands of patients diagnosed with brain cancer each year. Such diagnostic technologies are also appropriate for hospitals and physicians interested in advancing patient-centered care.
—Andrea Downing Peck