Overexpression of HIF-1α in primary gallbladder carcinoma and its relation to vasculogenic mimicry and unfavourable prognosis.
ABSTRACT As a novel mode of tumor neovascularization, vasculogenic mimicry (VM) has been reported to increase tumor-related mortality in many different solid tumors. In the present study, two established human gallbladder carcinoma (GBC) cell lines (highly aggressive GBC-SD and poorly aggressive SGC-996) cultured on a three-dimensional matrix were assessed for the ability of VM channel formation under normoxic or hypoxic conditions. In addition, the relationship between HIF-1α gene expression and VM channel formation of GBC cells in vitro was measured using the small interfering RNA (siRNA) technique, western blotting and real-time reverse transcription (RT)-PCR analysis. Furthermore, H&E and CD31/periodic acid-Schiff (PAS) staining were used to observe VM in GBC tissue samples. Additionally, all seventy-one specimens with VM and non-VM were stained for hypoxia inducible factor-1 α (HIF-1α) and its correlation with clinicopathological features and prognosis was analyzed simultaneously. We found that hypoxia could induce more VM channel formation and elevated HIF-1α expression in highly aggressive GBC-SD cells. HIF-1α siRNA efficiently knocked down HIF-1α expression and GBC VM networks under either normoxic or hypoxic conditions. VM was present in human primary GBC and overexpression of HIF-1α was significantly correlated with depth of invasion and perineural involvement in the non-VM group. Moreover, VM and HIF-1α were independent factors for the overall survival of GBC patients and correlated with decreased survival. In conclusion, VM was present in human GBC. As a critical mediator in VM formation, high expression of HIF-1α was associated with VM and tumor progression in GBC patients.
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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.PLoS ONE 01/2014; 9(5):e96982. · 3.73 Impact Factor
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ABSTRACT: Vasculogenic mimicry (VM) has been reported in various malignant tumours and is known to play an important role in cancer progression and metastasis. However, the impact of VM on the overall survival of human cancer patients remains controversial. The goal of this study was to evaluate whether VM is associated with 5-year survival of human cancer patients. Twenty-two eligible clinical studies with data on both tumour cell-dominant VM and the 5-year survival of 3062 patients involved in 15 types of cancers were pooled in the meta-analysis. The 5-year overall survival of VM-positive and -negative cancer patients was 31% and 56%, respectively. The relative risk (RR) of the 5-year survival of VM-positive patients was significantly higher than that of VM-negative cases (RR=1.531; 95% confidence interval (CI): 1.357-1.726; P<0.001). Notably, metastatic melanoma patients demonstrated a higher VM rate (45.3%) than patients with primary melanoma (23.1%) and showed worse 5-year survival, suggesting that VM contributes to tumour metastasis and poor prognosis in cancer patients. Subgroup analysis indicated that a poor 5-year survival was significantly associated with eight types of VM-positive malignant tumours, such as lung, colon, liver cancers, sarcomas and melanoma; but was not associated with the seven other types of cancers, such as prostate cancer. Heterogeneity and publication biases were found among the 22 studies, mainly due to the divergent characteristics of cancers and extremely low survival rate in six types of malignant tumours. VM-positive cancer patients show a poor 5-year overall survival compared with VM-negative malignant tumour cases, particularly in metastatic cancer.European journal of cancer (Oxford, England: 1990) 08/2013; · 4.12 Impact Factor
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ABSTRACT: Vasculogenic mimicry (VM) is a novel tumor blood supply in some highly aggressive malignant tumors. Recently, we reported VM existed in gallbladder carcinomas (GBCs) and the formation of the special passage through the activation of the PI3K/MMPs/Ln-5gamma2 signaling pathway. GBC is a highly aggressive malignant tumor with disappointing treatments and a poor prognosis. Norcantharidin (NCTD) has shown to have multiple antitumor activities against GBCs, etc; however the exact mechanism is not thoroughly elucidated. In this study, we firstly investigated the anti-VM activity of NCTD as a VM inhibitor for GBCs and its underlying mechanisms. In vitro and in vivo experiments to determine the effects of NCTD on proliferation, invasion, migration, VM formation, hemodynamic and tumor growth of GBC-SD cells and xenografts were respectively done by proliferation, invasion, migration assays, HE staining and CD31-PAS double staining, optic/electron microscopy, tumor assay, and dynamic micro-MRA. Further, immunohistochemistry, immunofluorescence, Western blotting and RT-PCR were respectively used to examine expression of VM signaling-related markers PI3-K, MMP-2, MT1-MMP and Ln-5gamma2 in GBC-SD cells and xenografts in vitro and in vivo. After treatment with NCTD, proliferation, invasion, migration of GBC-SD cells were inhibited; GBC-SD cells and xenografts were unable to form VM-like structures; tumor center-VM region of the xenografts exhibited a decreased signal in intensity; then cell or xenograft growth was inhibited. Whereas all of untreated GBC-SD cells and xenografts formed VM-like structures with the same conditions; the xenograft center-VM region exhibited a gradually increased signal; and facilitated cell or xenograft growth. Furthermore, expression of MMP-2 and MT1-MMP products from sections/supernates of 3-D matrices and the xenografts, and expression of PI3-K, MMP-2, MM1-MMP and Ln-5gamma2 proteins/mRNAs of the xenografts were all decreased in NCTD or TIMP-2 group; all P < 0.01, vs. control group); NCTD down-regulated expression of these VM signaling-related markers in vitro and in vivo. NCTD inhibited tumor growth and VM of human GBCs in vitro and in vivo by suppression of the PI3-K/MMPs/Ln-5gamma2 signaling pathway. It is firstly concluded that NCTD may be a potential anti-VM agent for human GBCs.BMC Cancer 03/2014; 14(1):193. · 3.33 Impact Factor