Controlling mammalian gene expression with small molecules.

Several systems are now available that enable transcription of a gene introduced into mammalian cells to be controlled using small molecules. Among the potential applications are the analysis of gene function through creation of inducible alleles in cell culture and transgenic animals, and, ultimately, the pharmacological control of therapeutic protein production in vivo in the context of gene therapy. Highlights of the past year include several demonstrations of regulated protein production in animal models of gene and cell therapy, and the development of a new approach to transcriptional regulation using chemical inducers of dimerization.