The present invention provides for improved therapeutic regimens for treating benign hyperproliferative diseases and cancers. The Egr-1 promoter, long known to be radiation-responsive, has now been shown to be inducible for DNA damaging chemical agents, many of which themselves are used in therapies. Thus, the present invention provides for the advantageous combination of a DNA damaging chemical and an expression vector containing a therapeutic gene driven by the Egr-1 promoter.