RNA interference for therapy in the vascular endothelium.

RNA interference (RNAi) has become an indispensable tool for loss of function analysis in today's basic cell biological research, and is currently being utilized for developing novel therapeutic methods. Systemic administration of synthetic small interfering RNA (siRNA) into the bloodstream is a feasible route for targeting the vascular endothelium or peripheral blood cells. The vascular endothelium can be considered an organ by itself, involved in many pathophysiological processes. Here, we aim to summarize current strategies of using RNAi for analysis of gene function in endothelial (in vitro loss-of-function analysis) and of exploiting RNAi for therapeutic purposes in order to suppress disrupted gene expression ("RNAi therapeutics"). With respect to the latter, we will summarize recent experimental concepts as well as ongoing therapeutic applications of RNAi mediated suppression of gene expression modulating angiogenic processes in cancer and retinopathies. We will further discuss the opportunities, prospects, challenges and potential fallbacks as well as the present strategies for the realization of "RNAi therapeutics" in combating vascular diseases.