Washington Post (01/04/93), P. A3 (Rensberger, Boyce)

A type of genetic engineering is being performed by scientists who are seeking a cure for AIDS and other maladies. The technique is called "antisense" technology because it tells cells to do the opposite of what one of their genes is instructing them to do. For example, genetic instruction could be a message coming from a strain of HIV that has fooled a blood cell into making new HIV strains. The antisense technique makes it possible to send another message that cancels the gene's instruction before the cell can act on it. The process has been shown to inhibit the proliferation of viruses in cultured cells infected with HIV, herpes, and cervical cancer. The antisense technology inhibits the essential middle step in the series of events by which genes control cells. Each gene holds coded instructions telling the cell how to assemble raw materials to make a protein molecule. The genetic instruction is transcribed into a temporary replica called messenger RNA. This molecule delivers the code to one of the cell's protein factories--a ribosome--outside the nucleus. This apparatus reads the messenger RNA's code and assembles the given protein. The antisense technique is intended to kill the messenger RNA before it can be read by a ribosome. This is accomplished by putting into the cell a synthetic form of DNA that will bind to the targeted RNA molecules but not to other messenger RNA segments carrying different instructions needed by the cell. The synthetic DNA binds because it carries a genetic message, which is virtually a mirror image of the RNA's message.