EphB4 as a therapeutic target in breast cancer: Monoclonal antibody screening using a 3D biomimetic model

Overview

Topic status: We're looking for students to study this topic.

Background: In 2007, 12,567 women were diagnosed with breast cancer (BCa) in Australia alone and these numbers will increase significantly in the next decade. Despite advances in targeted therapies such as Herceptin and Avastin, these drugs are only suitable for some women and BCa phenotypes and most treatments for advanced disease focus on relieving symptoms and extending a woman's life. It is critical that new options for treatment are developed as a matter of urgency. We have identified the receptor tyrosine kinase EphB4 as a potential prime target for monoclonal antibody (MAb) therapeutic strategies and this promises to be an important advance in the clinical management of this disease [1-3].

We have developed a panel of 10 MAbs that target the extracellular domain of EphB4 and have successfully tested one of these (C2) in an in vivo mouse model of human BCa. Critically, C2 did not have an effect on cell growth in cell culture monolayers, highlighting a crucial difference between outcomes of standard in vitro screening approaches on tissue culture plastic and in vivo efficacy, the fundamental requirement of any potentially useful MAb therapeutic. Advances in the development of three-dimensional (3D) in vitro cell systems have produced models that more accurately mimic in vivo tissue microenvironments and offer affordable, ethical and biologically relevant alternatives to using animal models for screening potential therapeutic agents [4]. This project will use an innovative 3D co-culture model of human BCa cells and associated fibroblasts that represent the tumour microenvironment, to identify 2 lead Mabs from our panel of 10 that then can be tested in a pre-clinical mouse model of metastatic BCa (potential for extension to PhD project).

Hypothesis/Aims: We hypothesise that EphB4 is an attractive target for MAb anti-BCa therapies. We base this hypothesis on the following studies:

  • EphB4 is over-expressed in breast cancer cells and it contributes to cancers such as breast cancer by promoting angiogenesis, increasing cancer cell survival and facilitating invasion and migration
  • Our preliminary in vivo data shows a MAb targeting a particular epitope in the extracellular domain of EphB4 dramatically reduces the growth of BCa MDA-MB-231 xenograft tumours

Aim: To use an innovative in vitro biomimetic 3-dimensional (3D) model that reflects the primary intra-mammary microenvironment to test our panel of 10 unique anti-EphB4 MAbs against BCa cell lines to identify lead antibodies for subsequent testing in vivo.

Approaches

  • Cell culture
  • 3D co-culture of breast cancer cells and fibroblasts using polyethylene glycol-based hydrogels [4]
  • Cell viability, proliferation and apoptosis assays
  • Immunohistochemistry, immunofluorescence and confocal laser scanning microscopy

References

  1. Stephenson, S.A., et al., Receptor protein tyrosine kinase EphB4 is up-regulated in colon cancer. BMC Mol Biol, 2001. 2: p. 15.
  2. Novel EphB4 monoclonal antibodies modulate angiogenesis and inhibit tumor growth. Am J Pathol, 2010. 176(4): p. 2029-38.
  3. Kumar, S.R., et al., Receptor tyrosine kinase EphB4 is a survival factor in breast cancer. Am J Pathol, 2006. 169(1): p. 279-93.
  4. Loessner, D., et al., Bioengineered 3D platform to explore cell-ECM interactions and drug resistance of epithelial ovarian cancer cells. Biomaterials, 2010. 31(32): p. 8494-506.
Study level
PhD, Honours
Supervisors
QUT
Organisational unit

Science and Engineering Faculty

Research area

Cell and Molecular Biosciences

Contact
Please contact the supervisors.