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.
Atsushi Natsume, MD, PhD (above), Associate Professor at Nagoya University, led the research team that created the simple, liquid biomarker urine test for central nervous system tumors that achieved 100% sensitivity and 97% specificity, regardless of the tumor’s size or malignancy. Such a non-invasive clinical laboratory test used clinically would be a boon to brain cancer diagnosis worldwide. (Photo copyright: Nagoya University.)
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.
Use of such precision diagnostics offer ‘early detection, localization, and the opportunity to monitor response to therapy,’ say the MIT scientists
Oncologists and medical laboratory scientists know that most clinical laboratory tests currently used to diagnose cancer are either based on medical imaging technologies—such as CT scans and mammography—or on molecular diagnostics that detect cancer molecules in the body’s urine or blood.
Now, in a study being conducted at the Massachusetts Institute of Technology (MIT), researchers have developed diagnostic nanoparticles that can not only detect cancer cells in bodily fluids but also image the cancer’s location. This is the latest example of how scientists are combining technologies in new ways in their efforts to develop more sensitive diagnostic tests that clinical laboratories and other providers can use to detect cancer and other health conditions.
Precision diagnostics such as molecular, imaging, and analytics technologies are key tools in the pursuit of precision medicine.
“Therapeutic outcomes in oncology may be aided by precision diagnostics that offer early detection, localization, and the opportunity to monitor response to therapy,” the authors wrote, adding, “Through tailored target specificities, this modular platform has the capacity to be engineered as a pan-cancer test that may guide treatment decisions for numerous tumor type.”
Development of Multimodal Diagnostics
The MIT scientists are developing a “multimodal” diagnostic that uses molecular screening combined with imaging techniques to locate where a cancer began in the body and any metastases that are present.
“In principle, this diagnostic could be used to detect cancer anywhere in the body, including tumors that have metastasized from their original locations,” an MIT new release noted.
“This is a really broad sensor intended to respond to both primary tumors and their metastases,” said biological engineer Sangeeta Bhatia, MD, PhD (above), in the news release. Bhatia is the John and Dorothy Wilson Professor of Health Sciences and Technology and Electrical Engineering and Computer Science at MIT and senior author of the study.
“It can trigger a urinary signal and also allow us to visualize where the tumors are,” she added. Bhatia previously worked on the development of cancer diagnostics that can produce synthetic biomarkers which are detectable in urine samples.
“The vision is that you could use this in a screening paradigm—alone or in conjunction with other tests—and we could collectively reach patients that do not have access to costly screening infrastructure today,” said Sangeeta Bhatia, MD, PhD (above), in the MIT news release. “Every year you could get a urine test as part of a general check-up. You would do an imaging study only if the urine test turns positive to then find out where the signal is coming from. We have a lot more work to do on the science to get there, but that’s where we would like to go in the long run.” (Photo copyright: NBC News.)
Precision Diagnostic Assists Assessment of Response to Cancer Therapy
For their research, the scientists added a radioactive tracer known as copper-64 to the nanoparticles. This enabled the particles to be used for positron emission tomography (PET) imaging. The particles were coated with a peptide that induced them to accumulate at tumor sites and insert themselves into cell membranes, producing a strong imaging signal for tumor detection.
The researchers tested their diagnostic nanoparticles in mouse models of metastatic colon cancer where tumor cells had traversed to the liver or the lungs. After treating the cancer cells with a chemotherapy regimen, the team successfully used both urine and imaging to determine how the tumors were responding to the treatment.
Bhatia is hopeful that this type of diagnostic could be utilized in assessing how patients are responding to treatment therapies and the monitoring of tumor recurrence or metastasis, especially for colon cancer.
What is unique about the approach used by Bhatia’s team is that one application of the copper-64 tracer can be used in vivo, in combination with imaging technology. The other application of the copper-64 tracer is in vitro in a urine specimen that can be tested by clinical laboratories.
“Those patients could be monitored with the urinary version of the test every six months, for instance. If the urine test is positive, they could follow up with a radioactive version of the same agent for an imaging study that could indicate where the disease had spread,” Bhatia said in the news release. “We also believe the regulatory path may be accelerated with both modes of testing leveraging a single formulation.”
The graphic above, taken from the MIT news release, shows how “multimodal nanosensors (1) are engineered to target and respond to hallmarks in the tumor microenvironment. The nanosensors provide both a noninvasive urinary monitoring tool (2) and an on-demand medical imaging agent (3) to localize tumor metastasis and assess response to therapy,” the news release states. (Photo and caption copyright: Massachusetts Institute of Technology.)
Precision Medicine Cancer Screening Using Nano Technologies
Bhatia hopes that the nanoparticle technology may be used as a screening tool in the future to detect any type of cancer.
Her previous research with nanoparticle technology determined that a simple urine test could diagnose bacterial pneumonia and indicate if antibiotics could successfully treat that illness, the news release noted.
Nanoparticle-based technology might be adapted in the future to be part of a screening assay that determines if cancer cells are present in a patient. In such a scenario, clinical laboratories would be performing tests on urine samples while imaging techniques are simultaneously being used to diagnose and monitor cancers.
Surgical pathologists may also want to monitor the progress of this research, as it has the potential to be an effective tool for monitoring cancer patients following surgery, chemotherapy, or radiation therapy.
