LIPID-MEDIATED AND ADENOVIRAL-MEDIATED GENE-TRANSFER INTO AIDS KAPOSIS-SARCOMA CELL-LINES

Kaposi's sarcoma (KS) is the most frequent malignancy occurring in HIV -positive individuals. AIDS-KS is a more aggressive disease than the c lassical form, frequently having a rapid clinical course with numerous serious complications. Current systemic treatments for KS, such as ch emotherapy and the administration of biological modifiers, are complic ated by both the drug resistance of the tumor and the dose-limiting to xicity of the reagents. The relative accessibility of many KS lesions makes the disease a particularly attractive candidate for in vivo gene therapy protocols. In this regard, we are interested in delivering co nditionally toxic suicide and/or antiangiogenic vectors to accomplish targeted cell death selectively in AIDS-KS cells. To this end, we exam ined both cationic lipid-and adenoviral-mediated DNA transfection meth ods. Using the firefly luciferase reporter gene, we optimized numerous variables known to be important in lipid-mediated DNA transfection, i ncluding lipid formulation, the amount of lipid and DNA, lipid/DNA rat io, and cell concentration. Under optimal transfection conditions, sim ilar to 5-25% of KS cells expressed the introduced DNA sequences. Aden oviral-mediated DNA delivery was more efficient than lipid delivery in 4 of 5 primary KS cell lines. Two of the lines (RW248 and RW376) were transduced by adenovirus at frequencies approaching 100%; two cell li nes (CVU-1 and RW80) gave efficiencies of 20-35%. Two immortalized KS cell lines (KS Y-1 and KS SLK) were poorly infected, giving a transduc tion efficiency of <5%. These findings demonstrate that gene transfer into AIDS-KS cells is feasible, and suggest that vector strategies may be permissive for translating gene therapy approaches for the disease .