Norcantharidin enhances TIMP-2 anti-vasculogenic mimicry activity for human gallbladder cancers through downregulating MMP-2 and MT1-MMP

Abstract

Vasculogenic mimicry (VM) is a tumor microcirculation pattern in highly aggressive gallbladder cancers (GBCs). We recently reported the anti-VM activity of norcantharidin (NCT D) in highly aggressive GBC- SD cells and xenografts. In this study, we further investigated that NCT D enhanced tissue inhibitor of matrix metalloproteinase-2 (TI MP-2) anti-VM activity for GBCs and the underlying mechanisms. In vivo and in vitro experiments were performed to determine the effects of NCT D in combination with TI MP-2 on tumor growth, host survival, VM formation, hemodynamic of GBC- SD xenografts, and VM-like networks and malignant phenotypes of GBC- SD cells. Expression of matrix metalloproteinase (MMP)-2 and membrane type 1-MMP (MT1-MMP) among human GBCs, GBC- SD cells and xenografts were determined, respectively. The results showed that expression of MMP-2 and MT1-MMP in human GBCs, GBC-SD cells and xenografts was significantly related to VM in GBCs; a shorter survival time of VM-positive patients with high expression of MMP-2 or MT1-MMP compared to that of the patients with low expression. After treatment with NCT D+TI MP-2, tumor growth, VM formation, VM hemodynamic of the xenografts in vivo were significantly inhibited as compared to control, NCTD or TI MP-2 group, with a prolonged survival time of the xenograft mice (log-rank test, P=0.0115); and these observations were confirmed by VM-like networks by 3-D matrices and showed that proliferation, apoptosis, invasion, migration of GBC- SD cells in vitro were markedly affected. Furthermore, expression of MMP-2 and MT1-MMP in VM formation of the xenografts in vivo and GBC-SD cells in vitro was downregulated as compared to control, NCT D or TI MP-2 group. Thus, we concluded that NCT D enhances TI MP-2 antitumor and anti-VM activities in GBCs through downregulating MMP-2 and MT1-MMP.