Pericyte-targeting prodrug overcomes tumor resistance to vascular disrupting agents
Minfeng Chen, … , Dongmei Zhang, Wencai Ye
Minfeng Chen, … , Dongmei Zhang, Wencai Ye
Published August 28, 2017
Citation Information: J Clin Invest. 2017;127(10):3689-3701. https://doi.org/10.1172/JCI94258.
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Concise Communication Oncology

Pericyte-targeting prodrug overcomes tumor resistance to vascular disrupting agents

Abstract

Blood vessels in the tumor periphery have high pericyte coverage and are resistant to vascular disrupting agents (VDAs). VDA treatment resistance leads to a viable peripheral tumor rim that contributes to treatment failure and disease recurrence. Here, we provide evidence to support a hypothesis that shifting the target of VDAs from tumor vessel endothelial cells to pericytes disrupts tumor peripheral vessels and the viable rim, circumventing VDA treatment resistance. Through chemical engineering, we developed Z-GP-DAVLBH (from the tubulin-binding VDA desacetylvinblastine monohydrazide [DAVLBH]) as a prodrug that can be selectively activated by fibroblast activation protein α (FAPα) in tumor pericytes. Z-GP-DAVLBH selectively destroys the cytoskeleton of FAPα-expressing tumor pericytes, disrupting blood vessels both within the core and around the periphery of tumors. As a result, Z-GP-DAVLBH treatment eradicated the otherwise VDA-resistant tumor rim and led to complete regression of tumors in multiple lines of xenografts without producing the drug-related toxicity that is associated with similar doses of DAVLBH. This study demonstrates that targeting tumor pericytes with an FAPα-activated VDA prodrug represents a potential vascular disruption strategy in overcoming tumor resistance to VDA treatments.

Authors

Minfeng Chen, Xueping Lei, Changzheng Shi, Maohua Huang, Xiaobo Li, Baojian Wu, Zhengqiu Li, Weili Han, Bin Du, Jianyang Hu, Qiulin Nie, Weiqian Mai, Nan Ma, Nanhui Xu, Xinyi Zhang, Chunlin Fan, Aihua Hong, Minghan Xia, Liangping Luo, Ande Ma, Hongsheng Li, Qiang Yu, Heru Chen, Dongmei Zhang, Wencai Ye

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Figure 2

Z-GP-DAVLBH is selectively hydrolyzed by FAPα to release DAVLBH to disrupt the cytoskeleton of FAPα-expressing pericytes.

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Z-GP-DAVLBH is selectively hydrolyzed by FAPα to release DAVLBH to disru...
(A) Structure of Z-GP-DAVLBH. (B) Evaluation of the enzymatic kinetics of rhFAPα on Z-GP-DAVLBH. The substrate-velocity curve for cleavage of Z-GP-DAVLBH by rhFAPα (5 ng/ml) is shown (n = 3). (C) Enzymatic efficacy of engineered FAPα-expressing cells on Z-GP-DAVLBH. HEK-293T cells were transiently transfected with vector, WT FAPα, or mutant FAPα plasmids (R123A, E203A, E204A, Y656F, N704A). Z-GP-DAVLBH (10 μM) was cocultured with cells at 37°C for 2 hours, and hydrolysis was analyzed by LC/MS. Quantification of the hydrolysis rate is shown (n = 3). N.H., no hydrolysis. (D) Evaluation of the hydrolysis for Z-GP-DAVLBH in MDA-MB-231 tumor xenografts (n = 5). The concentrations of Z-GP-DAVLBH and DAVLBH in tumors were detected at 5, 30, and 60 minutes after i.v. injection of Z-GP-DAVLBH (2.0 μmol/kg). (E) Enzymatic ability of HBVPFAPα-WT, HBVPNC, HBVPs, HUVECs, and MDA-MB-231 against Z-GP-DAVLBH. Quantification of the hydrolysis rate is shown (n = 3). (F) Inhibition of tubulin polymerization by DAVLBH and Z-GP-DAVLBH in vitro. Purified porcine brain tubulin was incubated with the tested compounds at 1 μM. Effects on tubulin polymerization were monitored by fluorescence value measurement, with excitation at 360 nm and emission at 420 nm every 1 minute for 90 minutes at 37°C. Paclitaxel (3 μM) was used as positive control agent. (G) The effect of Z-GP-DAVLBH on the β-tubulin cytoskeleton of HBVPFAPα-WT, HBVPNC, HBVPs, HUVECs, and MDA-MB-231 cells (n = 3). The cells were treated with Z-GP-DAVLBH (2.5 nM) for 30 minutes, and β-tubulin (green) and F-actin (red) were observed with a confocal microscope. Data are shown as mean ± SEM. Scale bar: 50 μm.