LIPOFECTIN-AIDED CELL DELIVERY OF RIBOZYME TARGETED TO HUMAN UROKINASE RECEPTOR MESSENGER-RNA

A 37-mer hammerhead ribozyme has been designed to efficiently cleave t he 1.4 kb mRNA of the urokinase plasminogen activator receptor (uPAR). Under in vitro conditions, the chemically synthesized ribozyme cleave d uPAR mRNA and inhibited its translation in a concentration-dependent fashion. The ribozymes were 5'-[S-35]thiophosphorylated and used as a model to analyze conditions for RNA delivery in a cultured human oste osarcoma cell system. Ribozymes degraded immediately in cell-condition ed medium but ribozymes complexed with lipofectin were protected from RNases for up to 22 h. Lipofectin rapidly transported ribozyme into th e cell, where it accumulated almost exclusively in the cytoplasm. Thus , lipofectin dramatically enhances stability and cytoplasmic delivery of ribozymes, potentially enabling targeting of mRNA in vivo.