Urine test may help to detect brain tumours early

Researchers from Nagoya University have revealed that microRNAs in urine could be a promising biomarker to diagnose brain tumours, possibly leading to improved patient survival. Their findings have been published in the journal ACS Applied Materials & Interfaces.

Early diagnosis of brain tumours is often difficult, partly because most people undergo a brain CT or MRI scan only after the onset of neurological deficits, such as immobility of limbs and incapability of speech. When brain tumours are detected by CT or MRI, they have in many cases already grown too large to be fully removed, which could lower patients’ survival rate. Accurate, easy and inexpensive methods of early brain tumour detection are therefore desirable.

As a diagnostic biomarker of cancerous tumours, microRNAs (tiny molecules of nucleic acid) have recently received considerable attention. MicroRNAs are secreted from various cells and exist in a stable and undamaged condition within extracellular vesicles in biological fluids like blood and urine. Nagoya University researchers focused on microRNAs in urine as a biomarker of brain tumours, with corresponding author Associate Professor Atsushi Natsume noting that urine is a substance that “can be collected easily without putting a burden on the human body”.

“Urine-based liquid biopsy hadn’t been fully investigated for patients with brain tumours, because none of the conventional methodologies can extract microRNAs from urine efficiently in terms of varieties and quantities,” Dr Natsume continued. “So we decided to develop a device capable of doing it.”

The researchers developed a device that is equipped with 100 million zinc oxide nanowires, which can be sterilised and mass-produced and is therefore suitable for medical use. The device can extract a significantly greater variety and quantity of microRNAs from only a millilitre of urine compared to conventional methods, the researchers found. Furthermore, their analysis of microRNAs collected from the urine of patients with brain tumours and non-cancer individuals revealed that many microRNAs derived from brain tumours actually exist in urine in a stable condition.

The researchers examined whether urinary microRNAs can serve as a biomarker of brain tumours, using their diagnostic model based on the expression of microRNAs in urine samples from patients with brain tumours and non-cancer individuals. The results showed that the model can distinguish the patients from non-cancer individuals at a sensitivity of 100% and a specificity of 97%, regardless of the malignancy and size of tumours. The researchers thus concluded that microRNAs in urine is a promising biomarker of brain tumours.

The researchers hope that their findings will contribute to early diagnosis of aggressive types of brain cancer, like glioblastomas, as well as other types of cancer.

Image credit: ©stock.adobe.com/au/peterschreiber.media

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