Approaches to gene therapy with sodium/iodide symporter

Since cloning and characterization of the sodium iodide symporter (NIS) gene, several investigators explored the possibility of a novel cytoreductive gene therapy strategy based on NIS gene transfer into non-thyroidal tumor cells followed by radioiodine therapy. NIS gene transfer has been shown to be capable of inducing radioiodine accumulation in vitro and in vivo in several non-thyroidal cancer cell lines. Following PSA promoter-mediated NIS gene delivery we were able to demonstrate prostate-specific iodide accumulation in prostate cancer cells that was high enough to elicit a therapeutic response of 131-I in vitro and in vivo. This study clearly demonstrates the potential of NIS as a novel therapeutic gene for non-thyroidal cancers, in particular prostate cancer.