Carboxylesterases (CESs) and Histone deacetylases (HDACs) are regarded as important signaling enzymes highly associated with the development and progression of multiple cancers, including hepatocellular carcinoma (HCC). In this work, a near-infrared (NIR) fluorescent probe named Lys-HXPI was designed and synthesized, which linked a hemicyanine dye and 6-acetamidohexanoic acid via an ester bond. Lys-HXPI displayed a remarkable increase with a NIR emission at 720 nm, a low detection limit (<10 nM) for HDAC1, HDAC 6, CES1 and CES2, as well as a high selectivity for the target enzymes over other relevant analytes. Furthermore, Lys-HXPI was used to image endogenous target enzymes in living cells, tumor-bearing nude mice and tissue slices. The ability of Lys-HXPI to simultaneous image CESs and HDACs was demonstrated with RT-qPCR and the confocal imaging in Hep G2 and MDA-MB-231. Taking advantage of NIR emission, the probe was also successfully applied to imaging Hep G2 tumor mice and tissue slices. Lys-HXPI is expected to be useful for the effective detecting of CESs and HDACs in complex biosystems.
Keywords: Carboxylesterases; Fluorescent probe; Hemicyanine; Histone deacetylases; Simultaneous imaging.
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