title: Association of Notch1 with vasculogenic mimicry in human hepatocellular carcinoma cell lines.
abstract: OBJECTIVE
  According to recent findings, some tumor cells function as endothelial progenitor cells to initiate tumor vasculogenesis, known as "vasculogenic mimicry" (VM). Notch1, the key regulator of vasculogenesis and embryonic differentiation, has shown a correlation with a poor prognosis in hepatocellular carcinoma (HCC). We attempted to elucidate the relationship between Notch1 and the vascularization of HCC.
  
  
  METHODS
  HCC cell lines were assayed for tube formation and low-density lipoprotein (LDL) absorption. The translation level of targets of interest was verified using western blot. Notch1 was silenced in HepG2, BEL-7402 and HCCLM6 using lentivirus shRNA. A hypoxic culture was conducted in an anaerobic culture chamber to induce VM in HepG2. Samples from 53 patients with HCC, i.e., 5 with metastasis and 48 without were tested for Notch1(+) cells and CD34 negative plus Periodic Acid-Schiff (PAS) positive structures, respectively.
  
  
  RESULTS
  BEL-7402 and HCCLM6 were capable of tube formation and LDL absorption in vitro, while HepG2 was negative for both. Notch1 down-regulation suppressed endothelial marker expression and greatly impaired tube formation. After hypoxic culture, the tube formation capacity of HepG2 was significantly enhanced, along with an increase in Notch1 expression. Notch1 was strongly and profusely expressed in all 5 cases of distant metastasis, while 19 of the 48 cases without metastasis were sparsely positive (P < 0.05). Notch1 positivity was mainly seen in the cytoplasm and nuclei. VM structures were only found in 2 cases from the metastasis group (P < 0.05).
  
  
  CONCLUSIONS
  HCC is capable of VM. Notch1 might serve as a potential target for VM development in HCC.
authors.affiliation: Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Research Center of Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China ; Department of Hepato-Pancreato-Biliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China.
authors.forename: Man-Sheng
authors.initials: MS
authors.lastname: Zhu
authors.affiliation: Department of Hepato-Pancreato-Biliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China.
authors.forename: Lei-Bo
authors.initials: LB
authors.lastname: Xu
authors.affiliation: Department of Pathology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Research Center of Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China ; Department of Hepato-Pancreato-Biliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China.
authors.forename: Xiang-De
authors.initials: XD
authors.lastname: Shi
authors.affiliation: Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Research Center of Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China ; Department of Hepato-Pancreato-Biliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China.
authors.forename: Wen-Rui
authors.initials: WR
authors.lastname: Wu
authors.affiliation: Department of Hepato-Pancreato-Biliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University Guangzhou 510120, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D015687:Cell Hypoxia; D066026:Endothelial Progenitor Cells / Q000378:metabolism* / Q000473:pathology; D056945:Hep G2 Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply* / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018716:Molecular Mimicry; D009389:Neovascularization, Pathologic; D034622:RNA Interference; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection
chemical_list: C497761:NOTCH1 protein, human; D051881:Receptor, Notch1
keywords: Notch1; hepatocellular carcinoma; vasculogenesis