DNA microarray

Until recently, cancer researchers laboriously studied one gene at a time. But advances in molecular biology and computer science are combining to accelerate cancer exploration. In particular, a new tool called the gene chip, invented by Stanford biochemist Patrick Brown, is now allowing researchers to sort through thousands of genes at a time, doing the work of years in just a few days.

The gene chip, known more technically as a DNA microarray, is a thumbnail-size glass wafer embedded with thousands of genes. Despite its name, the chip has no relation to a microprocessor and involves just a few simple steps to produce and use. In fact, many labs are building their own machines to make the chips. Each gene chip analysis gives a readout of the distinct patterns of genes switched on or off in a cell, effectively letting the researcher peer inside and get a comprehensive snapshot of the cellular dynamics at work. "[It's] the molecular microscope of modern cancer research," says Todd Golub, associate professor of pediatrics at Harvard Medical School and director of cancer genomics at the Whitehead/MIT Center for Genome Research.

Some cancers have been considered simply too complex to decipher at the genetic level, and scientists have chosen not to spend their limited time on them. But molecular profiling might put even those tumors on the radar screen. One example is multiple myeloma, a cancer of the blood that afflicts 15,000 new people a year. Now, using gene chips, John Shaughnessy of the University of Arkansas for Medical Sciences has already begun to make sense of the genetic chaos of multiple myeloma. Indeed, he now believes myeloma is really an umbrella term that describes at least four distinct types of disease. And in a recent study, he has identified several new possible drug targets for these variations. Of course, years of hard work lie ahead to further explore these novel targets and design therapies to strike them. But a huge step has been taken forward. "Instead of walking around in a dark room with a pin light," he says, "we are using a floodlight."

From U.S. News & World Report
http://www.usnews.com/usnews/health/articles/020624/archive_021674.htm