Urine contains "extracellular endoplasmic reticulum" (40-5000 nanometers in size), which is the endoplasmic reticulum secreted by cells, and contains "microRNA", which is a small RNA that controls biological functions.It has been thought that this microRNA is expressed differently in cancer patients and healthy subjects.However, although more than 2000 types of human microRNA have been found, only 200 to 300 types have been found by conventional technology using an ultra-high-speed rotating centrifuge (ultracentrifuge).Since there was no other technique for efficiently capturing extracellular endoplasmic reticulum in urine, it was considered difficult to diagnose cancer using urinary microRNA.

　This time, we have developed a new technology to capture extracellular endoplasmic reticulum in urine using nanoscale rods (zinc chloride nanowires).We discovered that the nanowire is a new material that captures more than 99% of extracellular endoplasmic reticulum in urine.In addition, when we analyzed the microRNAs inside the urinary extracellular endoplasmic reticulum captured by this nanowire, we discovered for the first time in the world that more than 1000 types of microRNAs are present in 1 mL of urine.

　Furthermore, comparing the urine of cancer patients with the microRNAs recovered from the urine of healthy subjects, we found microRNAs that were specifically overexpressed or decreased in cancer patients.In addition, we were able to discover cancer patient-specific microRNAs not only in urinary cancer patients (prostate / bladder) but also in non-urinary cancer patients (lung / pancreas / liver).

　By utilizing the technology developed this time, it is expected to diagnose and identify cancer that does not damage the living body (non-invasive) using urine.

Paper information:[Science Advances] Unveiling massive numbers of cancer-related urinary-microRNA candidates via nanowires