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

• Published in: PloS one 2014-05, Vol.9 (5), p.e96982
• Main Authors: Wang, Hui, Sun, Wei, Zhang, Wen-Zhong, Ge, Chun-Yan, Zhang, Jing-Tao, Liu, Zhong-Yan, Fan, Yue-Zu
• Format: Article
• Language: English
• Subjects: Adhesion; Angiogenesis; Animals; Antineoplastic Agents - pharmacology; Antineoplastic Agents - therapeutic use; Apoptosis; Biology and Life Sciences; Bridged Bicyclo Compounds, Heterocyclic - pharmacology; Bridged Bicyclo Compounds, Heterocyclic - therapeutic use; Cancer; Cancer therapies; Cell cycle; Cell Line, Tumor; Cell migration; Cell proliferation; Cell Proliferation - drug effects; Cell survival; Down-Regulation - drug effects; EphA2 protein; Ephrin-A2 - metabolism; Female; Focal adhesion kinase; Focal Adhesion Protein-Tyrosine Kinases - metabolism; Gallbladder; Gallbladder cancer; Gallbladder Neoplasms - blood supply; Gallbladder Neoplasms - drug therapy; Gallbladder Neoplasms - pathology; Gene expression; Hospitals; Humans; Immunofluorescence; In vivo methods and tests; Kinases; Male; Medical prognosis; Medical research; Medicine; Medicine and Health Sciences; Melanoma; Metastasis; Mice; Microcirculation - drug effects; Mimicry; Norcantharidin; Paxillin; Paxillin - metabolism; Polymerase chain reaction; Prolongation; Proteins; Research and Analysis Methods; Signal transduction; Signal Transduction - drug effects; Signaling; Surgery; Survival; Survival Analysis; Tumors; Western blotting; Xenograft Model Antitumor Assays; Xenografts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0096982

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.