CUHK Research: Changing the world

and bacteria, purified it with solution buffers, collected the cells that come off the surface of the colon, stained them with chemicals on slides and examined the cells under microscope to find any malignant cells. “That phase of our research was, frankly, unpleasant. Identifying malignment cells with the naked eye under microscopy was labour intensive and ultimately not sensitive enough. So, we had to find another way.” The CUHK team moved on to experiments with other possible biomarkers and found that a single-stranded, small non-coding RNA molecule — miR-92a — was the most stable, sensitive and cost-effective. Moreover, each test requires only 300 mg of stool sample per individual. Patent applications have been made to authorities in the US, Europe and Taiwan. As the gut microbiome emerges as a new frontier in medicine, Professor Yu, teaming with other CUHK gastroenterologists, has developed the world’s first faecal bacterial gene marker test for detecting colorectal cancer. It is now available commercially in private hospitals and clinics in Hong Kong. State approval Another non-invasive blood diagnostic kit developed by the CUHK team is based on a plasma (RNF180 methylation DNA) biomarker for gastric cancer screening and early diagnosis. With a superior performance to that of conventional blood protein detection methods, it was approved by the NMPA in 2020. It is the only NMPA-approved molecular detection kit available in mainland China for the early diagnosis of gastric cancer and is commonly applied in clinical practice. Given the rising incidence of cancer in the world, there will be increasing demand for improved diagnostic procedures to identify high-risk individuals. Professor Yu believes that these diagnostic kits, based on simple, low- These diagnostic kits, based on simple, low-cost tests on a PCR platform, should remain highly sustainable. cost tests on a polymerase chain reaction (PCR) platform, should remain highly sustainable. Detecting fatty liver disease Another research focus of Professor Yu is non-alcoholic fatty liver disease, the most common chronic liver disease globally. “Some Chinese people do not look obese. But if you check with ultrasound, their internal organs are full of fat. This is due to their rich westernised diet, which is low in fibre, and to a lack of exercise,” Professor Yu says. “Non-alcoholic steatohepatitis (NASH) is the more severe form of fatty liver disease and can progress silently towards cirrhosis and liver cancer,” Professor Yu cautions. “Liver biopsy remains the gold standard for its diagnosis, but it is limited in routine clinical practice due to its invasiveness and high cost, among other reasons. Many Chinese will not accept having a piece of their liver sliced,” she says. “That’s why we set out to find another way for early detection.” Recently, Professor Yu and her team discovered a group of blood-based biomarkers for diagnosis of NASH . She has applied for a patent for the technology on the mainland. This research on non-alcoholic fatty liver and its related cancer has, for the second time, earned Professor Yu and her CUHK colleagues the prestigious State Natural Science Award (second-class). 33