title: Transfer of the sFLT-1 gene in Morris hepatoma results in decreased growth and perfusion and induction of genes associated with stress response.
abstract: OBJECTIVE
  Inhibition of tumor angiogenesis is emerging as a promising target in the treatment of malignancies. Therefore, monitoring of antiangiogenic approaches with functional imaging and histomorphometrical analyses are desirable to evaluate the biological effects caused by this treatment modality.
  
  
  METHODS
  Using a bicistronic retroviral vector for transfer of the soluble receptor for the vascular endothelial growth factor (sFLT) hepatoma (MH3924A) cell lines with sFLT expression were generated. In human umbilical vein endothelial cells cultured with conditioned medium of sFLT-expressing hepatoma cells, the inhibitory action of secreted sFLT was determined using a Coulter counter and a thymidine incorporation assay. Furthermore, in vivo experiments were done to measure the effects on tumor growth and perfusion. Finally, the tumors were examined by immunohistochemistry (including computer-assisted morphometry) and DNA chip analysis.
  
  
  RESULTS
  Stable sFLT-expressing hepatoma cells inhibited endothelial cell proliferation in vitro. In vivo, growth and perfusion, as measured by H(2)(15)O positron emission tomography, were reduced in genetically modified tumors. However, the immunohistochemically quantified microvascularization and macrovascularization, as indicated by CD31- and alpha-actin-positive area, revealed no significant changes, whereas the number of apoptotic cells was increased in sFLT-expressing tumors, although not significantly. DNA chip analysis of tumors with gene transfer showed an increase of genes related to apoptosis, signal transduction, and oxidative stress.
  
  
  CONCLUSIONS
  Our results suggest that sFLT expression inhibits tumor growth and perfusion and enhances expression of apoptosis-related genes in this model. Enhanced expression of genes for signal transduction, stress, and metabolism indicates tumor defense reactions.
authors.affiliation: Department of Anatomy and Cell Biology III, University of Heidelberg, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schmidt
authors.forename: Johannes
authors.initials: J
authors.lastname: Hoffend
authors.forename: Annette
authors.initials: A
authors.lastname: Altmann
authors.forename: Ludwig G
authors.initials: LG
authors.lastname: Strauss
authors.forename: Antonia
authors.initials: A
authors.lastname: Dimitrakopoulou-Strauss
authors.forename: Britta
authors.initials: B
authors.lastname: Engelhardt
authors.forename: Dirk
authors.initials: D
authors.lastname: Koczan
authors.forename: Jörg
authors.initials: J
authors.lastname: Peter
authors.forename: Silke
authors.initials: S
authors.lastname: Vorwald
authors.forename: Helmut
authors.initials: H
authors.lastname: Eskerski
authors.forename: Michael
authors.initials: M
authors.lastname: Eisenhut
authors.forename: Jürgen
authors.initials: J
authors.lastname: Metz
authors.forename: Ralf
authors.initials: R
authors.lastname: Kinscherf
authors.forename: Uwe
authors.initials: U
authors.lastname: Haberkorn
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D017077:Culture Media, Conditioned; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D018014:Gene Transfer Techniques; D006801:Humans; D008114:Liver Neoplasms, Experimental / Q000235:genetics* / Q000473:pathology / Q000517:prevention & control*; D018384:Oxidative Stress / Q000235:genetics*; D049268:Positron-Emission Tomography; D011506:Proteins / Q000235:genetics*; D051381:Rats; D011923:Rats, Nude; D012190:Retroviridae / Q000235:genetics; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014471:Umbilical Veins / Q000378:metabolism / Q000473:pathology
chemical_list: D017077:Culture Media, Conditioned; D011506:Proteins; D013936:Thymidine