Research

[POSTECH and Linyi University develop ‘SLY,’ a Probe That Glows Yellow Only in Tumor Cells]

A collaborative research team led by Professor Young-Tae Chang from the Department of Chemistry at Pohang University of Science and Technology (POSTECH) and Professor Min Gao from Linyi University has successfully developed a novel fluorescent probe, SLY (Sialyl Lewis Yellow), capable of precisely identifying hepatocellular carcinoma tissue. The findings were published in the Journal of the American Chemical Society (JACS), a leading journal published by the American Chemical Society.

Glycans—carbohydrate structures present on the surface of cells—play pivotal roles in various biological processes, including cell-cell interactions, immune responses, and cancer metastasis. Among these, the sialyl Lewis family of glycans, particularly sialyl Lewis x (sLe^x) and sialyl Lewis a (sLe^a), are known to be overexpressed in several types of cancers, including liver cancer, positioning them as promising diagnostic markers. However, conventional techniques for analyzing glycans are complex and generally unsuitable for real-time imaging, underscoring the urgent need for fluorescent probes that can directly detect glycans in living cells.

The research team designed a library of fluorescent probes incorporating oxaborole as a recognition moiety and identified SLY as a probe capable of selectively targeting sialylated glycans on the cell surface. SLY demonstrated high affinity for sLe^x and sLe^a, which are overexpressed in hepatocellular carcinoma (HepG2) and colorectal cancer (HT29) cells. After binding to the target glycans, SLY is internalized via caveolae-mediated endocytosis and accumulates in the mitochondria.

In vivo and ex vivo experiments using cryo-sectioned liver cancer tissues confirmed the probe’s ability to selectively label cancerous regions with high fluorescence contrast. Notably, SLY outperforms conventional probes by clearly distinguishing tumor margins within liver tissues, suggesting strong potential for use in precision diagnostics and fluorescence-guided surgery.

Professor Young-Tae Chang, who led the study, commented,

“SLY represents the first fluorescent probe capable of selectively identifying sialylated glycans on the cell surface with such precision, enabling the identification of liver cancer at the cellular level. This work opens new possibilities in glycan-based cancer diagnostics and may lay the groundwork for future applications in fluorescence-guided surgery and precision medicine.”

This research was supported by the National Research Foundation of Korea (NRF) under the Ministry of Science and ICT through the Mid-Career Researcher Program and the Glocal University 30 initiative (POSTECH Molecular Imaging Center). Additional support was provided by the TIPS program of the Ministry of SMEs and Startups (Korea), the National Natural Science Foundation of China, the Shandong Overseas High-Level Talent Program, and the Taishan Scholar Program.

DOI: https://pubs.acs.org/doi/10.1021/jacs.5c03020