A near-infrared probe for detection of gamma-glutamyl transferase

Abstract

Cancer is known to be among the most harmful diseases to have been researched on for so many years, yet it remains difficult to eradicate. It is essential to diagnose and treat cancer in patients early to prevent major harmful symptoms and possibly prevent death. Fluorescence imaging has gained attention in recent years for cancer cell imaging due to its high selectivity, spatial recognition, sensitivity and non-invasive procedures. Hence, in this research study, we have obtained a fluorescence probe, BIX-Glu, which emits fluorescence in the near-infrared region of light, when subjected to an enzyme known as gamma-glutamyl transferase (GGT). GGT is an enzyme overexpressed in cancer cells, which cleaves off the gamma-glutamyl amide from BIX-Glu, releasing the chromophore benzoindolium xanthene. This cleavage causes the probe with no fluorescence emission, to transform into the fluorescence emitting chromophore. We tested the probe for cytotoxicity as well as cell imaging to determine its potential in detecting GGT in cancer cells. Our research shows promising results on the use of BIX-Glu as an activatable probe to detect GGT, the disease biomarker, using fluorescence imaging techniques.