Diagnosing cancer with light: Scientists develop a probe that glows yellow only in tumor cells

Sadie Harley
scientific editor

Robert Egan
associate editor

A collaborative research team has successfully developed a novel fluorescent probe, SLY (Sialyl Lewis Yellow), capable of precisely identifying hepatocellular carcinoma tissue. The findings are in the Journal of 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 (sLex) and sialyl Lewis a (sLea), 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, 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, 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 sLex and sLea, 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."
More information: Kwangwook Ko et al, Oxaborole-Functionalized Sialylated Glycan Probe for High-Fidelity Fluorescence Imaging of Cancer Tissue, Journal of the American Chemical Society (2025).
Journal information: Journal of the American Chemical Society
Provided by Pohang University of Science and Technology