Cholesterol is an important modulator of membrane protein function and signaling in endothelial cells, thus making it an emerging target for anti-angiogenic agents. In this study, we employed a phenotypic screen that detects intracellular cholesterol distribution in endothelial cells (HUVEC) and identified 13 existing drugs as cholesterol trafficking inhibitors. Cepharanthine, an approved drug for anti-inflammatory and cancer management use, was amongst the candidates, which was selected for in-depth mechanistic studies to link cholesterol trafficking and angiogenesis. Cepharanthine inhibited the endolysosomal trafficking of free-cholesterol and low-density lipoprotein in HUVEC by binding to Niemann-Pick disease, type C1 (NPC1) protein and increasing the lysosomal pH. The blockade of cholesterol trafficking led to a cholesterol-dependent dissociation of mTOR from the lysosomes and inhibition of its downstream signaling. Cepharanthine inhibited angiogenesis in HUVEC and in zebrafish in a cholesterol-dependent manner. Furthermore, cepharanthine suppressed tumor growth in vivo by inhibiting angiogenesis and it enhanced the antitumor activity of the standard chemotherapy cisplatin in lung and breast cancer xenografts in mice. Altogether, these results strongly support the idea that cholesterol trafficking is a viable drug target for anti-angiogenesis and that the inhibitors identified among existing drugs, such as cepharanthine, could be potential anti-angiogenic and antitumor agents.
Bibliographical noteFunding Information:
This work was supported by the Science and Technology Development Fund (FDCT) of Macau SAR ( FDCT/119/2013/A3 and FDCT/024/2015/A1 to J.S.S); Multi-Year Research Grant of the University of Macau ( MYRG2015-00181-FHS and MYRG2017-00176-FHS to J.S.S); NRF grant ( 2015K1A1A2028365 and 2015M3A9C4076321 to H.J.K); PhRMA Foundation Fellowship in Pharmacology/Toxicology (to S.A.H); National Cancer Institute Grant ( R01CA184103 to J.O.L); the Flight Attendant Medical Research Institute (to J.O.L); Prostate Cancer Foundation (to J.O.L); and the Johns Hopkins Institute for Clinical and Translational Research , which is funded in part by Grant UL1 TR 001079 from the National Center for Advancing Translational Sciences (NCATS) .
© 2017 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Cancer Research