A Bioluminescent Probe for Simultaneously Imaging Esterase and Histone Deacetylase Activity in a Tumor

The monitoring of esterase (CES) and histone deacetylase (HDAC) activity in living cells has great potential for rapid diagnosis of malignant tumors. At present, using one bioluminescence (BL) probe to simultaneously detect (or image) these two enzymes' activity in tumors has not been reported. Herein, a bioluminescence "turn-on" probe AcAH-Luc (6-acetamidohexanoic acid-d-luciferin) was rationally designed for simultaneously imaging CES and HDAC activity with excellent sensitivity and selectivity. AcAH-Luc was successfully applied in vitro to selectively detect CES and HDAC6, a subtype of HDAC, at a linear concentration range of 0-100 and 0-120 nM with limits of detection (LODs) of 0.495 and 1.14 nM, respectively. In vivo results indicated that about 1/2 and 1/3 of the "turn-on" BL signal of AcAH-Luc was contributed by CES and HDAC activity in the tumors, respectively. We envision that AcAH-Luc might be applied to simultaneously measure (and image) CES and HDAC activity in the clinic for assisting with the precise diagnosis of malignant tumors in the near future.