Scientists have developed a new device which can identify a key membrane protein in urine, that can be used to detect brain tumours. Since the device can identify the protein in urine, it avoids the need for invasive tests. The protein can indicate whether a patient has brain cancer, and hence, increases the likelihood of tumours being detected early enough for surgery.
The study, conducted by researchers at Nagoya University in Japan, was recently published in the journal ACS Nano.
Why has the survival rate for brain tumours remained unchanged?
The study could help researchers find ways to detect other types of cancers. Early detection of many types of cancer has contributed to the recent increases in cancer survival rates. However, the survival rate for brain tumours has remained almost unchanged for over 20 years. The reason behind this is the late detection of brain tumours.
When can a brain tumour be detected?
An initial neurological symptom in people with brain tumours is the loss of movement or speech. It is only after the onset of these symptoms that physicians discover brain tumours. However, by that time, the tumour reaches a considerable size.
In order to save lives, it is important to detect the tumour when it is still small, and start the treatment as soon as possible.
What are tumour-related extracellular vesicles?
The presence of tumour-related extracellular vesicles (EVs) in one's urine could be a possible sign that the person has a brain tumour. These are nano-sized vesicles involved in a variety of functions, including cell-to-cell communication.
How can EVs be used to detect the presence of cancer?
The EVs found in brain cancer patients have specific types of RNA and membrane proteins. Hence, they could be used to detect the presence of cancer and its progression.
Despite being excreted far from the brain, many EVs from cancer cells exist stably and are excreted in the urine without breaking down. According to a statement released by Nagoya University, Takao Yasui, one of the authors on the paper, said liquid biopsy can be performed using many body fluids, and that urine testing has many advantages. He stated that blood tests are invasive, but urine tests are an effective, simple and non-invasive method because the urine contains many informative biomolecules that can be traced back to identify the disease.
How does the new device work?
The researchers have developed a new analysis platform for brain tumour EVs using nanowires at the bottom of a well plate. They identified two specific types of EV membrane proteins from urine samples of brain tumour patients, using the device. These membrane proteins are known as CD31 and CD63. If doctors can detect these tell-tale proteins, they will be able to identify tumour patients before they develop symptoms.
Yasui said currently, EV isolation and detection methods require more than two instruments and an assay to isolate and then detect EVs. However, the all-in-one nanowire assay can isolate and detect EVs using one simple procedure.
Yasui added that in the future, users can run samples through the nanowire assay and change the detection part, by selectively modifying it to detect specific membrane proteins or miRNAs (microRNAs) inside EVs to detect other types of cancer.
Yasui further said that using this platform, the researchers 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.