Novel strategy for accurate tumor labeling: endogenous metabolic imaging through metabolic probes

Altered metabolism has long been recognized as a central hallmark of cancer; however, in the fluorescence imaging field, few studies have been conducted to label tumors by exploiting metabolic differences between cancer cells and normal cells. In this work, we successfully developed a metabolic probe MB-C for specific imaging of glutathione (GSH) dynamic metabolic pathways. GSH was endogenously metabolized to produce SO 2 via Na 2 S 2 O 3 and thiosulfate sulfurtransferase, equilibrating with sulfites/bisulfites. MB-C was allowed to be activated by GSH along with multi-fluorescence emission increased in red and green channels and further sequence-response metabolites (SO 2 ) of GSH in significant fluorescence ratio change of red and green channels. Furthermore, such evident fluorescence ratio changes could be used to distinguish cancer cells from normal cells and identify tumor and normal tissues. Therefore, GSH metabolic imaging was successfully applied to accurately label tumors, which provides a new idea and practical case for the precise visualization of malignant tumors.