Thursday, February 16, 2006

Why Cancer Strikes Some

Continued from page 1

By Emily Singer

New technologies could also help scientists understand some medical mysteries of our time -- such as rising asthma rates, which have doubled in the last two decades. Since the publication of the human genome sequence in 2003, scientists have focused enormous amounts of energy on the genetic basis of disease. "But genes don't tell the whole story," says Schwartz. "The recent increases in asthma, diabetes, and autism are not due to changes in our genome over last couple of decades. These major shifts point to the role our diet, activity levels, and environment play in disease."

"Scientists can now precisely measure genetic variation between individuals, but we can't accurately measure the individual variation in exposure or response to exposure...when faced with environmental challenges," Schwartz says. The new program hopes to fill that gap.

This timely program will take advantage of the explosion of information about the genome sequence, says Gerald N. Wogan, professor of chemistry and biological engineering at MIT. For example, scientists already know that people carry different forms of enzymes that detoxify chemicals, and that specific variants increase the risk of bladder cancer. But these new tools would allow scientists to do this kind of research on a much broader scale, he says.

Esteban González Burchard, a scientist at the University of California, San Francisco, believes that these kinds of tools will also help researchers understand complex diseases, such as asthma. His team, for instance, has shown that people with a particular genetic background are more likely to develop asthma when exposed to secondhand smoke. But the environmental contribution to asthma is probably even more complex, he says, with factors such as socioeconomic status also playing a role. And new technologies could help scientists sort out these complex factors.