ZEB1Promote The Vasculogenic Mimicry In Colon Cancer

Background and ObjectiveColon cancer (CC) is one of the most common cancers worldwide. Although CC diagnosis and treatment have significantly advanced over the past two decades, the death rate of CRC patients has not improved. Vasculogenic mimicry (VM), a unique microcirculation pattern, is closely related to tumor invasion and tumor-related death. This study aimed at clarifying the relationship between VM and clinical and pathological parameters, thus evaluating the significance of VM in clinical treatment and prognotic indication, and further exploring the possible mechanism of epithelial-mesenchymal transition (EMT) regulated by zinc finger E-box binding homeobox1(ZEB1) on VM formation in colon cancer.Methods:1) H&E staining and PAS-CD34dual staining were used to detect VM existencein203colon cancer tissue;2) IHC staining was used to detect the expression of the ZEB1and EMT markers;3) Three-dimensional culture (3D) was used to investigate the VM formation of three colon cancer cell lines in vitro, western blotting was used to detect the expression of endothelial-associated proteins (VE-cadherin,Flt-1,Flk-1).4) ZEB1was downregulated by SiRNA technology in HCT116cells and the influence of ZEB1knockdown on tube structure formation and expression of endothelial-associated proteins were detected;5) Western blotting and immunofluorescent staining were used to detect the expression of EMT-associated proteins;6) Wound healing and invision assays were performed to detect the influence of ZEB1on cell movement and invasion of colon cancer;7) Stem-like cell associated proteins were detected by western blotting.Results:1) VM exists in colon cancer and the incidence is19.2%; 2) The presence of VM was associated with aggressive biological behavior and was an unfavorable prognostic indicator;3) Univariateanalysis showed VM and ZEB1expression were related to overall survival. Multivariate analysis indicated that VM was an independent predictor for overall survival;4) Immunohistochemical analysis showed that the VM-positive CC samples expressed higher ZEB1than the VM-negative samples, and ZEB1expression occurred concomitantly with features of EMT;5) Compared with VM-negative samples, VM-positive samples showed lower expression of E-cadherin and higher expression of Vimentin;6) Among the three colon cancer cell lines, only the poorly differentiated HCT116cells could form vessel-like structures in the3D culture and expressed the endothelial-associated proteins;7) Knockdown of ZEB1induced restoration of epithelial phenotype and destroyed the property of vascular-like tube formation in HCT116cells;8) The ZEB1-downexpressed HCT116cells showed higher expression of E-cadherin, claudin4and lower expression of Vimentin, Fibronectin. ZEB1knockdown in HCT116cells significantly inhibited the ability to migrate and invade;9) The ZEB1-downexpressed HCT116cells showed lower expression of stem cell-associated protein CD44.Conclusions:1) VM exists in colon cancer;2) VM contributed to progression of colon cancer and is an unfavorable prognostic indicator;3) In colon cancer, ZEB1may participate in VM formation by regulating EMT;4) VM formation may be related to stem cell-like characteristics of colon cancer.