| Background and ObjectiveEsophageal cancer is a common digestive tract cancer, the incidence andmortality rates are high. Early esophageal cancer may be asymptomatic or onlysternum discomfort, burning sensation, intermittent dysphagia, foreign body sensationand a very mild symptoms, not causes patients and their families and more attentionand timely treatment, so most patients already belongs to the clinical treatment lateclinical efficacy is poor, and poor prognosis. The fast progress of cancer, theprognosis is poor, closely related to the tumor’s blood supply.The main role of the vascular network within the tumor consists of two aspects,first ensure that the tumor cells for oxygen, nutrients and metabolites excreted inorder to promote tumor growth; while its wall structure is not complete, thebasement membrane of varying thickness, which is tumor cells into the lumen of theblood channel which occurred in turn provide convenient conditions. Previousstudies of people on tumor vascular network system focused onendothelium-dependent angiogenesis, first discovered the network-like vascular structures (Vasculogenic mimicry, VM) from Maniotis in highly invasive uvealmelanoma after another in liver cancer, breast cancer, colorectal cancer, renal cellcancer, esophageal cancer and other tumors were found to have the presence of thephenomenon of VM and VM confirmed the formation and tumor metastasis,invasion, was positively correlated with poor prognosis. VM refers to mimicembryonic vasculogenesis highly invasive ability of tumor cells in the network mode,which is independent of the vascular endothelium-dependent, is involved by thetumor cells form a complex network consisting of vascular blood flow in the lumenof the host blood vessel and interlinked, tumor growth and metastasis can providegood blood perfusion. Studies have shown that hypoxia can promote the formation ofesophageal VM, but the exact mechanism is unclear, Bcl-2-mediated VE-cadoverexpressing breast cancer may promote the formation of VM. But whether thesame mechanism, further research is needed in the formation of esophageal cancercells in the VM.Methods1．Using Cocl2chemically induced human esophageal cancer cell lines Ec9706formed anoxic microenvironment.2．In hypoxic microenvironment in Bcl-2-siRNA interference human esophagealsquamous cell carcinoma cell lines Ec9706.3．rder to develop human esophageal cancer cell Ec9706, and placed in aninverted fluorescence microscope to observe each experimental group (normoxiccontrol group, hypoxia group, hypoxia empty vector group, hypoxia experimentsgroup) shape and the number of pipeline structure formation.4．Flow cytometry was used to detect interference after each experimental group(normoxic control group, hypoxia group, hypoxia empty vector group, hypoxiaexperimental group) cell proliferation.5．RT-PCR assay to detect each experimental group (normoxic control group,hypoxia group, hypoxia empty vector group, hypoxia experimental group) the mRNAexpression of VM related molecule Bcl-2, VE-cadherin and MMP2. 6．Detected by Western blot in each experimental group (normoxic control group,hypoxia group, hypoxia empty vector group, hypoxia experimental group) the proteinexpression of VM related molecules Bcl-2, VE-cadherin and MMP2.Results1． Three-dimensional culture system to observe the formation of tubularstructures in each experimental group number： hypoxia group formed morenetwork-like tubular structure than normoxic control group,(P <0.000); A significantreduction in hypoxia carried out Bcl-2-siRNA interference network-like tubularstructure in the experimental group than the control group and the empty vectorhypoxia group (P <0.000); rather empty vector control group and hypoxia group werenot significantly different (P=0.051) directly;2．Cell apoptosis was detected by flow cytometry in each experimental group：Normoxic control group, hypoxia group, hypoxia empty vector group，hypoxia in theexperimental group, the apoptosis rate was6.17±0.17,0.6±0.12,1.2±0.12,22.63±0.37, apoptosis hypoxia control group rate was significantly lower than in normoxiccontrol group (P <0.05), the experimental group was significantly stronger hypoxichypoxia apoptosis rate in the control group (P <0.05);3．PCR assay the VM-related molecules mRNA expression of each experimentalgroup：hypoxia control group Bcl-2and VE-cadherin mRNA expression weresignificantly higher than normoxic control group (P <0.05), hypoxia in theexperimental group Bcl-2, VE-cadherin, MMP2expression was significantly lower(P <0.05). No significant differences between the control group and hypoxichypoxia empty vector group(P>0.05);4．Western-blot assay VM-related molecules the protein expression in eachexperimental group：Western-blot assay VM-related molecules in each experimentalgroup protein expression, hypoxia control group Bcl-2, VE-cadherin proteinexpression were significantly higher than normoxic control group P <0.05), hypoxiaexperimental group Bcl-2, VE-cadherin, MMP2expression of hypoxia comparedwith the control group was significantly lower (P <0.05), no statistically significant difference (P between the control group and hypoxic hypoxia empty vector>0.05).ConclusionHypoxia can induce the formation of esophageal cancer cells Ec9706vasculogenic mimicry，and Bcl-2-dependent VE-cadherin overexpression inducedunder hypoxia may be an important molecular mechanism VM. |
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