Study gives new insight into diagnosing ovarian cancer

Nagoya [Japan], July 10 : Research headed by Nagoya University in Japan discovered three previously unknown membrane proteins in ovarian cancer. The scientists captured the proteins using a novel technique comprised of nanowires with a polyketone coating, providing a new detection tool for ovarian cancer.

The identification of novel biomarkers is critical for identifying ovarian cancer since the illness is difficult to detect in its early stages, when it may be treated most effectively. Extracellular vesicles (EVs), particularly tiny proteins produced from tumours known as exosomes, are one method for identifying cancer. These proteins may be separated from bodily fluids such as blood, urine, and saliva since they are located outside the cancer cell. However, the application of these biomarkers for the identification of ovarian cancer is hampered by a paucity of trustworthy ones.

A research group led by Akira Yokoi of the Nagoya University Graduate School of Medicine and Mayu Ukai at the Institute for Advanced Research extracted both small and medium/large EVs from high-grade serous carcinoma (HGSC), the most common type of ovarian cancer, and analyzed them using liquid chromatography-mass spectrometry to analyze the proteins.

Initially their research was challenging. "The validation steps for the identified proteins were tough because we had to try a lot of antibodies before we found a good target," said Yokoi. "As a result, it became clear that the small and medium/large EVs are loaded with clearly different molecules. Further investigation revealed that small EVs are more suitable biomarkers than the medium and large type. We identified the membrane proteins FRa, Claudin-3, and TACSTD2 in the small EVs associated with HGSC."

Now that the group had identified the proteins, they investigated whether they could capture EVs in a way that would allow for the identification of the presence of cancer. To do this, they turned to nanowire specialist Takao Yasui of the Graduate School of Engineering at Nagoya University who combined his research with that of Dr Inokuma at the Japan Science and Technology Agency to create polyketone chain-coated nanowires (pNWs). This technology was ideal for separating exosomes from blood samples.

"pNW creation was tough," Yokoi said. "We must have tried 3-4 different coatings on the nanowires. Although polyketones are a completely new material to use to coat this type of nanowire, in the end, they were such a good fit."

"Our findings showed that each of the three identified proteins is useful as a biomarker for HGSCs," said Yokoi. "The results of this research suggest that these diagnostic biomarkers can be used as predictive markers for specific therapies. Our results allow doctors to optimize their therapeutic strategy for ovarian cancer, therefore, they may be useful for realizing personalized medicine."