antisense rna to the type i insulin-like growth factor receptor reversed the transformed phenotype of pc-3 human prostate cancer cell line in vitro

the insulin-like growth factor i receptor (igf-ir) plays an essential role in the establishment and maintenance of transformed phenotype. interference with the igf-ir pathway by antisense causes reversal of the transformed phenotype in many rodent and human tumor cell lines. we stably transfected the pc-3 human prostate cancer cell line with an igf-ir antisense rna expression plasmid. the number of igf-i receptors on the antisense-transfected pc-3 cells was reduced by 40.2% relative to the control-transfected cells. the transfected cells maintained their high expression of igf-ir antisense rna for up to one year in selective medium . the reduction in the expression of igf-ir had no effect on the cell growth in monolayer. the clonogenicity of antisense-transfected cells was 24.7% of the clonogenicity of control-transfected cells in soft agar. there was a good correlation between igf-ir level and inhibition of transformation in soft agar. these results indicate that reduction of igf-ir by antisense rna can reverse the transformed phenotype of human prostate cancer cells.