PE, a new sulfated saponin from sea cucumber, exhibits anti-angiogenic and anti-tumor activities in vitro and in vivo.
Here, we examined the in vitro and in vivo anti-angiogenesis and anti-tumor activities of PE, a new marine-derived compound. Inhibition of angiogenesis was assessed in vitro using proliferation, migration, adhesion, tube-formation and apoptosis assays in PE-treated HMECs and HUVECs. In vivo, CAM assays were used to assess inhibition effect of PE on physiological angiogenesis, and immunofluorescent microscopy was used to examine tumor microvessel density and apoptosis in PE-treated mouse tumor models. Finally, Western blotting analyses were performed to examine the effect of PE on VEGF signaling in HMECs. The results showed that PE inhibited proliferation of HMECs and HUVECs with IC50 values of 2.22 +/- 0.31 microM and 1.98 +/- 0.32 microM, induced endothelial cell apoptosis at concentrations <2 microM, induced dose-dependent suppression of cell migration, cell adhesion and tube formation in HMECs and HUVECs, and showed anti-proliferative activities against several tumor cell lines (IC50 values of approximately 4 microM). In vivo, PE (5 nM/egg) suppressed spontaneous angiogenesis in our CAM assay, and induced marked growth inhibition in mouse sarcoma 180 and hepatoma 22 models. Specifically, PE treatment reduced mouse sarcoma 180 tumor volume by triggering apoptosis of both tumor and tumor-associated endothelial cells, preferentially targeting on endothelial cells comparable with tumor cells. Finally, PE treatment suppressed the active (phosphorylated) forms of VEGFR2, Akt, ERK, FAK and paxillin, which are involved in endothelial cell survival, proliferation, adhesion and migration. Our results indicate that PE exerts an anti-angiogenic activity associated with inhibition of VEGFR2 signaling, and an anti-tumor activity associated with decreased proliferation of tumor cells and increased apoptosis of both endothelial cells and tumor cells.
Tian
Fang
F
Division of Anti-Tumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, PR China.
Zhang
Xiongwen
X
Tong
Yunguang
Y
Yi
Yanghua
Y
Zhang
Shilong
S
Li
Ling
L
Sun
Peng
P
Lin
Liping
L
Ding
Jian
J
D020533:Angiogenesis Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis; D001681:Biological Assay; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002642:Chick Embryo; D049033:Chorioallantoic Membrane / Q000098:blood supply / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects; D006801:Humans; D051379:Mice; D009369:Neoplasms / Q000098:blood supply / Q000188:drug therapy*; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D010766:Phosphorylation / Q000187:drug effects; D012503:Saponins / Q000494:pharmacology / Q000627:therapeutic use*; D012616:Sea Cucumbers / Q000737:chemistry; D014443:Tyrosine / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors*
D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; C511443:PE saponin, Pentacta quadrangularis; D012503:Saponins; D042461:Vascular Endothelial Growth Factor A; D014443:Tyrosine; D040301:Vascular Endothelial Growth Factor Receptor-2