1695P - Fibroblast induced epithelial to mesenchymal transition (EMT) in a novel non-small cell lung cancer (NSCLC) model

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Basic Science
Lung and other Thoracic Tumours
Presenter Arno Amann
Authors A. Amann1, M. Zwierzina2, M. Bitsche2, G. Gamerith3, J. Huber4, S. Koeck4, J. Kelm5, W. Hilbe6, H. Zwierzina3
  • 1Innere Medizin, Medical University Innsbruck, 6020 - Innsbruck/AT
  • 2Anatomy, Histology And Embryology, Medical University Innsbruck, 6020 - Innsbruck/AT
  • 3Medical University Innsbruck, 6020 - Innsbruck/AT
  • 4Internal Medicine 1, Medical University Innsbruck, 6020 - Innsbruck/AT
  • 5Insphero Ag, Insphero AG, 8005 - Zürich/CH
  • 6Department Of Internal Medicine, Medical University Innsbruck, 6020 - Innsbruck/AT

Abstract

Introduction

Different molecular processes lead to metastatic spread and the occurrence of tumour cell resistance to therapeutic interventions. Among them, the epithelial to mesenchymal transition (EMT) process plays a key role. During EMT, epithelial tumour cells lose the expression of specific proteins and adopt the phenotype of mesenchymal cells. These structural conversions are substantially dependent on the tumour microenvironment. EMT of tumour cells can induce drug resistance and metastasis. Thus, EMT inhibition may offer a new strategy for overcoming tumour progression.

Methods

To evaluate EMT in a non-small cell lung cancer (NSCLC) model a 2D and a 3D- cell culture system was applied using both the human lung cancer cell line (A549) and the human lung fibroblast cell line (SV-80). For generating 3D cell spheroids, a novel system was established consisting of 96-well hanging drop microtiter plates (InSphero AG, Zürich, Switzerland). 2D co-culture assays were performed in transwell filter inserts (Costar). EMT was induced with transforming growth factor-� (TGF-�) or co-cultivation with fibroblasts in 2D/3D. The switch from epithelial to mesenchymal cells was monitored by Western Blot (WB) analyses of e-cadherin, vimentin and n-cadherin. Furthermore, immunohistochemical analyses of e-cadherin, vimentin, α-smooth muscle actin, fibronectin, KI-67 and CA-IX were done on paraffin embedded spheroids.

Results

EMT could be induced in the 2D not only by incubating tumour cells with TGF-� but also by co-culturing them with fibroblasts in transwell filter inserts. In A549 cells a change in morphology as well as in protein expression defined by WB analysis (down regulation: E-cadherin; up regulation; Vimentin, n-cadherin) could be detected. When cultivated in the 3D system, A549 cells showed an up regulation of the mesenchymal protein vimentin without TGF-ß stimulation. Furthermore, a significant up regulation of vimentin, KI-67, CA-IX, and a slight down regulation of e-cadherin could be measured compared to monocultures.

Conclusion

3D culture represents a model to study EMT in tumour cell lines without addition of growth factors and thus reflects in vivo conditions closer than 2D culture.

Disclosure

All authors have declared no conflicts of interest.