New Device Detects Brain Tumors Using Urine

By LabMedica International staff writers
Posted on 06 Feb 2023

Image: Microscopic image of the nanowires (Photo courtesy of Nagoya University)

There has recently been an improvement in cancer survival rates due to early detection of the disease, although the survival rate for brain tumors has remained almost the same for the last 20 years, partly due to their late detection. Brain tumors are often discovered only after the onset of neurological symptoms, such as loss of movement or speech, by when the tumor achieves a considerable size. Detecting the tumor when it is still small and commencing treatment as soon as possible can help save lives. Now, researchers have used a new device to identify a key membrane protein in urine that indicates whether a person has a brain tumor. By using the protein to detect brain cancer, it will be possible to avoid invasive tests and increase the chances of the tumor being detected at an early enough stage for surgery. The finding could also have potential implications for detecting other types of cancer.

The presence of tumor-related extracellular vesicles (EVs) in urine can indicate that a person has a brain tumor. EVs are nano-sized vesicles that perform various functions, including cell-to-cell communication. The EVs found in brain cancer patients have specific types of RNA and membrane proteins, allowing them to be used for detecting the presence of cancer and its progression. EVs are excreted far from the brain, but many EVs from cancer cells still exist stably and are excreted in the urine without breaking down.

Researchers at Nagoya University (Nagoya, Japan) have developed a new analysis platform for brain tumor EVs using nanowires at the bottom of a well plate. They used the device to identify two specific types of EV membrane proteins, known as CD31/CD63, from the urine samples of brain tumor patients. By looking for these tell-tale proteins, doctors can identify tumor patients before they develop symptoms. Additionally, urine testing offers several advantages and is an effective, simple, and non-invasive method because urine contains many informative biomolecules that can be traced back to identify the disease.

“Currently, EV isolation and detection methods require more than two instruments and an assay to isolate and then detect EVs,” said Associate Professor Takao Yasui of Nagoya University Graduate School of Engineering. “The all-in-one nanowire assay can isolate and detect EVs using one simple procedure. In the future, users can run samples through our assay and change the detection part, by selectively modifying it to detect specific membrane proteins or miRNAs inside EVs to detect other types of cancer. Using this platform, we expect to advance the analysis of the expression levels of specific membrane proteins in patients’ urinary EVs, which will enable the early detection of different types of cancer.”

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Nagoya University