Inhibition of Tumor Vasculogenic Mimicry and Prolongation of Host Survival in Highly Aggressive Gallbladder Cancers by Norcantharidin via Blocking the Ephrin Type a Receptor 2/Focal Adhesion Kinase/Paxillin Signaling Pathway

Abstract

Vasculogenic mimicry (VM) is a newly-defined tumor microcirculation pattern in highly aggressive malignant tumors. We recently reported tumor growth and VM formation of gallbladder cancers through the contribution of the ephrin type a receptor 2 (EphA2)/focal adhesion kinase (FAK)/Paxillin signaling pathways. In this study, we further investigated the anti-VM activity of norcantharidin (NCTD) as a VM inhibitor for gallbladder cancers and the underlying mechanisms. In vivo and in vitro experiments to determine the effects of NCTD on tumor growth, host survival, VM formation of GBC-SD nude mouse xenografts, and vasculogenic-like networks, malignant phenotypes i.e., proliferation, apoptosis, invasion and migration of GBC-SD cells. Expression of VM signaling-related markers EphA2, FAK and Paxillin in vivo and in vitro were examined by immunofluorescence, western blotting and real-time polymerase chain reaction (RT-PCR), respectively. The results showed that after treatment with NCTD, GBC-SD cells were unable to form VM structures when injecting into nude mouse, growth of the xenograft was inhibited and these observations were confirmed by facts that VM formation by three-dimensional (3-D) matrix, proliferation, apoptosis, invasion, migration of GBC-SD cells were affected; and survival time of the xenograft mice was prolonged. Furthermore, expression of EphA2, FAK and Paxillin proteins/mRNAs of the xenografts was downregulated. Thus, we concluded that NCTD has potential anti-VM activity against human gallbladder cancers; one of the underlying mechanisms may be via blocking the EphA2/FAK/Paxillin signaling pathway.

Anti-angiogenic treatment promotes triple-negative breast cancer invasion via vasculogenic mimicry

“…21,25,38 VEcadherin can activate MMPs via the EphA2 signaling pathway. 39 Furthermore, hypoxia-induced Twist1 expression also induces MDA-MB-231 cells to generate more CSCs, which then promote VM channel formationin Matrigel. 25 Hence, hypoxia induced by blocking the VEGF pathway not only directly promotes TNBC tumor invasion but also accelerates VM.…”

Association between Tumor Vasculogenic Mimicry and the Poor Prognosis of Gastric Cancer in China: An Updated Systematic Review and Meta-Analysis

“…The VEGF and phosphoinositide 3-kinase/AKT pathway also exert positive feedback regulation in the process of VM formation [39]. EphA2 is a protein tyrosine kinase receptor commonly expressed in epithelial cells [40], and it contributes to VM formation by mediating the EphA2/FAK/Paxillin pathway[41–44]. In the Wnt/ β -catenin pathway, hypoxic conditions and microRNAs also take part in VM formation [45–47].…”

Integrin β1 is an essential factor in vasculogenic mimicry of human cancer cells

“…In addition, some reports suggested that FAK participates in VM formation in gallbladder cancer. 35,36 Thus, FAK is probably associated with VM formation through an ITGB1-dependent mechanism(s). Further studies are necessary to elucidate the signaling cascade of ITGB1-mediated VM formation.…”