Anti-gene therapy: the use of ribozymes to inhibit gene function

The ability of certain enzymatic RNA molecules, or ribozymes, to site-specifically cleave other RNA molecules opens new vistas in gene therapy. Ribozymes can be designed to target specifically a particular mRNA and inhibit protein expression, permitting 'anti-gene' therapy. Here, we describe the progress towards developing ribozymes for use in gene therapy applications. Significant advances have been made in understanding ribozyme transcription unit design and the first clinical tests of ribozyme safety in humans are soon to be initiated.