title: Contribution of the PI3K/MMPs/Ln-5γ2 and EphA2/FAK/Paxillin signaling pathways to tumor growth and vasculogenic mimicry of gallbladder carcinomas.
abstract: Vasculogenic mimicry (VM) is a new tumor blood supply in some highly aggressive malignant tumors. We previously reported VM in human gallbladder carcinomas, 3-D matrices in vitro and nude mouse xenografts in vivo of highly aggressive GBC-SD cells and its clinical significance. In this study, we further studied the underlying mechanisms of VM in gallbladder carcinomas via the 3-D matrix in vitro, the nude mouse xenografts in vivo of GBC-SD or SGC-996 cells, immunohistochemistry (H&E staining and CD31-PAS double staining), electron microscopy, expression of MMP-2, MT1-MMP, PI3K, Ln-5γ2, EphA2, FAK and Paxillin-P proteins/mRNAs determined by SABC, ELISA, immunofluorescence, western blotting and qRT-PCR, respectively. It was shown that all of untreated highly aggressive GBC-SD cells and xenografts formed vasculogenic-like structures within 2 weeks of seeding and injecting, and facilitated the growth of tumor cells or xenografts; whereas poorly aggressive SGC-996 cells or GBC-SD cells treated by TIMP-2 were unable to form the vasculogenic-like structures with the same conditions; and tumor xenograft growth was inhibited. Expression of MMP-2, MT1-MMP proteins/mRNAs from sections and supernates of 3-D matrix in vitro, expression of PI3K, MMP-2, MT1-MMP, Ln-5γ2, EphA2, FAK and Paxillin-P proteins/mRNAs from sections of xenografts in vivo in untreated GBC-SD group was upregulated significantly (all P<0.001); however, expression of these VM signal-related proteins/mRNAs in the SGC-996 group and GBC-SD treated by the TIMP-2 group was significantly downregulated (all P<0.001). Thus, we identified for the first time that highly aggressive GBC-SD cells formed VM in vitro and in vivo through the upregulation of PI3K/MMPs/Ln-5γ2 and/or EphA2/FAK/Paxillin signaling. PI3K/MMPs/Ln-5γ2 and EphA2/FAK/Paxillin as key signaling pathways in a coordinated manner contributed to tumor growth and VM of gallbladder carcinomas and provided novel targets that could be potentially exploited for therapeutic intervention of human gallbladder carcinomas.
authors.affiliation: Department of Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Xin-Sui
authors.initials: XS
authors.lastname: Lu
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Ge
authors.forename: Wen-Zhong
authors.initials: WZ
authors.lastname: Zhang
authors.forename: Yue-Zu
authors.initials: YZ
authors.lastname: Fan
mesh_terms: D000818:Animals; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism*; D005706:Gallbladder Neoplasms / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007797:Laminin / Q000235:genetics / Q000378:metabolism; D008297:Male; D008666:Metalloendopeptidases / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D051419:Paxillin / Q000235:genetics / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D036104:Receptor, EphA2 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: C400567:LAMC2 protein, human; D007797:Laminin; C496061:PXN protein, human; D051419:Paxillin; D019869:Phosphatidylinositol 3-Kinases; D036104:Receptor, EphA2; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; D008666:Metalloendopeptidases