Adenovirus-mediated antisense urokinase-type plasminogen activator receptor gene transfer reduces tumor cell invasion and metastasis in non-small cell lung cancer cell lines

The urokinase-type plasminogen activator (uPA) and its receptor (uPAR) play an important role in the proteolytic cascade involved in the metastasis of lung and other cancers. We report that the reduction in uPAR levels produc ed by an antisense strategy using an adenovirus construct (Ad-uPAR) in H129 9 cells, an invasive human lung cancer cell line that produces high levels of uPAR, resulted in a decrease of uPAR levels to 80-90% of those seen in c ells infected with mock or adenovirus (Ad)-cytomegalovirus vector controls. In addition, increasing the multiplicity of infection from 25 to 200 cause d a corresponding decrease in the level of uPAR protein within 5 days of tr eatment, as shown by Western blot analysis. Furthermore, the in vitro trans lation of total RNA levels of Ad-uPAR-infected H1299 cells in a rabbit reti culocyte lysate system caused a 50-70% decrease in uPAR inmunoprecipitate i n Ad-uPAR-infected cells relative to the levels in cells of mock and vector controls. The Matrigel invasion assay showed the invasion of H1299 cells a nd A549 cells infected with Ad-uPAR to be decreased by 70% relative to mock - and vector-infected controls. Infection of tumor cells with Ad-uPAR befor e implantation significantly reduced the incidence of lung metastasis by 85 % as compared with the control virus-infected cells injected into nude mice through the tail vein. Our collective results show that the uPAR system is a potential target of treatment for lung cancers.