(310e) Role of RhoGTPase and Cellular Contractility On Non-Viral Gene Transfer

Dhaliwal, A. - Presenter, University of California-Los Angeles

Gene delivery has widespread applications in gene therapy and regenerative medicine. However, non-viral gene delivery is severely limited by efficiency in vivo. Past studies aiming to improve the efficiency of non-viral gene delivery have focused on improving the vector system, while the microenvironment where the cells reside is typically neglected. Previously we have shown that density as well as identity of structural proteins like vitronectin, laminin, collagen I and IV, and fibronectin, in the cell environment can modulate gene expression for D1 mesenchymal cells. This indicates that differences in intracellular trafficking might be responsible for the differences in gene expression seen for different protein densities. Previous studies have correlated the extent of cell area to myosin light chain phosphorylation, integrin expression and to the level of active RhoGTPases in the cell. Here, we demonstrate that RhoGTPase and the contractility pathway is activated in response to ECM structural proteins and that its activation affects polyplex internalization and overall gene transfer efficiency. The investigation of the effects of the cellular microenvironment on non-viral gene transfer will result into a comprehensive understanding of the limitations of gene transfer, which could further improve the current methods and vectors used for non-viral gene delivery.