Abstract
Ophiopogonin D, a steroidal glycoside extracted from the Traditional Chinese Medicine Ophiopogon japonicus, shows anti-tumor property in several lines of cancers; however, its effect on triple-negative breast cancer (TNBC) has not been investigated. In this study, the anti-metastatic effect of Ophiopogonin D in TNBC cells as well as the underlying mechanism in such process was explored. Ophiopogonin D dose-dependently decreased cell proliferation of MDA-MB-231 cells. Meanwhile, Ophiopogonin D significantly inhibited TGF-β1-induced metastatic behavior of MDA-MB-231 cells, including EMT, anoikis resistance as well as migration and invasion, via suppressing MMP-9 activity. Mechanically, Ophiopogonin D achieved its effect through efficiently abolishing ITGB1 expression, thus reducing the phosphorylation of FAK, Src and AKT, as well as upregulating nuclear β-catenin. ITGB1 overexpression partly recovered Ophiopogonin D's inhibitory effect on metastatic behavior via activating MMP-9. These results demonstrated that Ophiopogonin D could suppress TGF-β1-mediated metastatic behavior of MDA-MB-231 cells by regulating ITGB1/FAK/Src/AKT/β-catenin/MMP-9 signaling axis, which might provide new insight for the control of TNBC metastasis.