|
| Microscopic image of nanowires. Credit: Dr Takao Yasui |
Researchers at Nagoya University in Japan have used a new device to identify
a key membrane protein in urine that indicates whether the patient has a
brain tumor. This protein could be used to detect brain cancer, avoiding the
need for invasive tests, and increasing the likelihood of tumors being
detected early enough for surgery. This research could also have potential
implications for detecting other types of cancer. The research was published
in ACS Nano.
Although early detection of many types of cancer has contributed to the
recent increases in cancer survival rates, the survival rate for brain
tumors has remained almost unchanged for over 20 years. Partly this is due
to their late detection. Physicians often discover brain tumors only after
the onset of neurological symptoms, such as loss of movement or speech, by
which time the tumor has reached a considerable size. Detecting the tumor
when it is still small, and starting treatment as soon as possible, should
help to save lives.
One possible sign that a person has a brain tumor is the presence of
tumor-related extracellular vesicles (EVs) in their urine. EVs are
nano-sized vesicles involved in a variety of functions, including
cell-to-cell communication. Because those found in brain cancer patients
have specific types of RNA and membrane proteins, they could be used to
detect the presence of cancer and its progression.
Although they are excreted far from the brain, many EVs from cancer cells
exist stably and are excreted in the urine without breaking down. Urine
testing has many advantages, explains Associate Professor Takao Yasui of
Nagoya University Graduate School of Engineering. "Liquid biopsy can be
performed using many body fluids, but blood tests are invasive," he said.
"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."
A research group led by Yasui and Professor Yoshinobu Baba of Nagoya
University's Graduate School of Engineering, in collaboration with Nagoya
University's Institute of Innovation for Future Society and the University
of Tokyo, has developed a new analysis platform for brain tumor EVs using
nanowires at the bottom of a well plate. Using this device, they identified
two specific types of EV membrane proteins, known as CD31/CD63, from urine
samples of brain tumor patients. Looking for these tell-tale proteins could
enable doctors to identify tumor patients before they develop symptoms.
"Currently, EV isolation and detection methods require more than two
instruments and an assay to isolate and then detect EVs," said Yasui. "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."
Reference:
Kunanon Chattrairat et al, All-in-One Nanowire Assay System for Capture and
Analysis of Extracellular Vesicles from an ex Vivo Brain Tumor Model, ACS
Nano (2023).
DOI: 10.1021/acsnano.2c08526