Oligonucleotides (ODNs) show great promise in their ability to specifically inhibit single gene expression but must cross the cell membrane, escape the endosomal vesicle, and possibly traverse the nuclear membrane to arrive at their intracellular target molecules. In an attempt to improve the delivery of phosphodiester triplex forming ODNs to malignant cells, we have constructed adenovirus-polylysine (AdpL)-ODN complexes designed to take advantage of the receptor mediated endocytosis and endosomolysis of adenoviruses to transfer the ODNs to the cell nucleus. Treatment of several different types of tumor cells in culture by AdpL-ODN complex resulted in superior uptake and persistence of the ODNs compared to both free ODN and cationic lipd-ODN complexes. Nuclear uptake peaks at 4 h and intact ODN persists in the nucleus with a half-life of 12 h. ODN concentrations of 20-70 μm are achieved at 24 h in all monolayer cell lined evaluated to date. ODNs are detected in 50-100% of the total cell population by immunohistochemisty with apparent uptake into vesicles and unclear localization. Luciferase expression of a co-delivered reporter plasmid suggests that these ODNs are free in the nucleus. AdpL-ODN complexes will provide a valuable tool for delivering unmodified ODNs to the nucleus of malignant cells.
|Number of pages||11|
|State||Published - Apr 1 1996|
- Gene therapy
- HER-2/neu oncogene
- Receptor mediated endocytosis
- k-ras oncogene