Efficacy of anti-death receptor 5 (DR5) antibody (TRA-8) against primary human ovarian carcinoma using a novel ex vivo tissue slice model

Gynecol Oncol. 2007 May;105(2):291-8. doi: 10.1016/j.ygyno.2006.12.033. Epub 2007 Feb 15.


Objectives: The purpose of this study was to evaluate the cytotoxicity of a death receptor 5 (DR5) targeting monoclonal antibody (TRA-8) in primary ovarian cancer specimens utilizing a tissue slice technique that allows for assessment of anti-tumor activity in a three-dimensional ex vivo model.

Methods: Nineteen primary ovarian tumor specimens were obtained at the time of cytoreductive surgery and tumor slices were prepared with the Krumdieck tissue slicer. Tumor slices were incubated with TRA-8 for 24 h and a dose-response curve was established for each specimen using non-linear modeling, with IC50 values used as the parameter of TRA-8 sensitivity. In parallel with ATP viability assays, TRA-8 treated and untreated tumor slices were assessed by immunohistochemistry (IHC) and western blot analysis to confirm apoptosis induction.

Results: Incubation with 0-1000 ng/ml TRA-8 resulted in a dose response with maximum killing observed at 1000 ng/ml compared to untreated control slices. IC50 values of 6.0 to >1000 ng/ml were calculated for individual tumor specimens. H&E, IHC, and western blot specimens demonstrated TRA-8-induced cellular death in a dose-dependent fashion via apoptosis and activation of caspases 3, 8, and 9. The apoptosis produced by varying concentrations of TRA-8 was confirmed using the TUNEL technique. Treatment with TRA-8 markedly reduced proliferation in the ovarian cancer cells as measured by expression of Ki-67/SP6.

Conclusions: This study demonstrates that targeting DR5 with TRA-8 decreases cellular proliferation, increases caspase activation, and induces apoptosis in this novel three-dimensional ex vivo model of primary ovarian cancer.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / pharmacology*
  • Blotting, Western
  • Drug Screening Assays, Antitumor
  • Female
  • Humans
  • Immunohistochemistry
  • Inhibitory Concentration 50
  • Middle Aged
  • Ovarian Neoplasms / immunology
  • Ovarian Neoplasms / pathology
  • Ovarian Neoplasms / therapy*
  • Receptors, TNF-Related Apoptosis-Inducing Ligand / immunology*


  • Antibodies, Monoclonal
  • Receptors, TNF-Related Apoptosis-Inducing Ligand