ADENOVIRUS ENHANCEMENT OF POLYETHYLENIMINE-MEDIATED TRANSFER OF REGULATED GENES IN DIFFERENTIATED CELLS

Efficient gene transfer is a prerequisite for analysing regulation of transfected promoters. We combined the DNA binding property of the cat ionic polymer polyethylenimine (PEI) and the potent endocytic activity of advenovirus in a PEI-DNA-adenovirus complex which provided efficie nt plasmid delivery in differentiated cultured cells. We transfected 3 T3-F442A adipocytes, C2.7 myocytes and FAO hepatoma cells with a const ruct containing the simian virus 40 promoter fused to the chlorampheni col acetyltransferase (CAT) gene, using a combination of PEI and 200 p .f.u. per cell of replication-deficient type 5 adenovirus. Resulting C AT activities varied according to the cell type reaching about 0.6, 8 and 38 units/mg protein for respectively 3T3-F442A, FAO and C2.7 cells . Increases in transfection efficiencies were 140- to 300-fold when co mpared with those obtained with PEI alone. Then we tested physiologica lly regulated promoters: the phosphoenolpyruvate carboxykinase gene pr omoter in 3T3-F442A or FAO cells and the hexokinase II gene promoter i n C2.7 myocytes. Gene expression was appropriately increased by clofib rate, dexamethasone and insulin for 3T3-F442A, FAO and C2.7 cells, res pectively. Thus, the combination of PEI and adenovirus is a simple, ef ficient, inexpensive and versatile method of gene transfer which is ap plicable to several differentiated cells and provides a physiologicall y coherent transgene regulation. We name this method PEI-adenofection.