EFFICIENT DELIVERY OF TRIPLEX FORMING OLIGONUCLEOTIDES TO TUMOR-CELLSBY ADENOVIRUS-POLYLYSINE COMPLEXES

Oligonucleotides (ODNs) show great promise in their ability to specifi cally inhibit single gene expression but must cross the cell membrane, escape the endosomal vesicle, and possibly traverse the nuclear membr ane to arrive at their intracellular target molecules. In an attempt t o improve the delivery of phosphodiester triplex forming ODNs to malig nant cells, we have constructed adenovirus-polylysine (AdpL)-ODN compl exes designed to take advantage of the receptor mediated endocytosis a nd endosomolysis of adenoviruses to transfer the ODNs to the cell nucl eus. Treatment of several different types of tumor cells in culture by AdpL-ODN complex resulted in superior uptake and persistence of the O DNs compared to both free ODN and cationic lipid-ODN complexes. Nuclea r uptake peaks at 4 h and intact ODN persists in the nucleus with a ha lf-life of 12 h. ODN concentrations of 20-70 mu M are achieved at 24 h in all monolayer cell lines evaluated to date. ODNs are detected in 5 0-100% of the total cell population by immunohistochemistry with appar ent uptake into vesicles and nuclear localization. Luciferase expressi on of a co-delivered reporter plasmid suggests that these ODNs are fre e in the nucleus. AdpL-ODN complexes will provide a valuable tool for delivering unmodified ODNs to the nucleus of malignant cells.