Abstract
Doxycycline have been reported to exert anti-cancer activity and have been assessed as anti-cancer agents in clinical trials. However, the direct targets of doxycycline in cancer cells remain unclear. In this study, we used a chemical proteomics approach to identify the Protease-activated receptor 1 (PAR1) as a specific target of inhibition of doxycycline. Binding assays and single-molecule imaging assays were performed to confirm the inhibition of doxycycline to PAR1. The effect of doxycycline on multi-omics and cell functions were assessed based on a PAR1/thrombin model. Molecular docking and molecular dynamic simulations revealed that doxycycline interacts with key amino acids in PAR1. Mutation of PAR1 further confirmed the computation-based results. Moreover, doxycycline provides highly selective inhibition of PAR1 signaling in tumors in vitro and in vivo. Using pathological clinical samples co-stained for doxycycline and PAR1, it was found that doxycycline fluorescence intensity and PAR1 expression shown a clear positive correlation. Thus, doxycycline may be a useful targeted anti-cancer drug that should be further investigated in clinical trials.
Highlights
The anti-tumor activity of tetracyclines has been verified in many tumor types, and doxycycline has been subjected to evaluation in clinical trials [1,2,3]
All tetracyclines were computationally docked with the active site of Protease-activated receptor 1 (PAR1), and the models exhibited similar binding modes (Supplementary Table 1)
We show that the inhibitory effects of doxycycline on cancer cells are mediated through PAR1
Summary
The anti-tumor activity of tetracyclines has been verified in many tumor types, and doxycycline has been subjected to evaluation in clinical trials [1,2,3]. Protease-activated receptor 1 (PAR1) is a member of the Guanosine-binding protein coupled receptor family, which has been implicated in metastatic and invasive processes associated with cancers as well as vascular biology and tissue remodeling [8]. Molecular docking results and molecular dynamic (MD) simulations confirmed the interaction between doxycycline and PAR1. This prediction was validated by biomolecular interaction analysis (Biacore) and mutational analyses. Doxycycline selectively inhibited the progression of various types of cancer associated with high PAR1 expression both in vitro and in vivo
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
