News Focus

Hunting for Collaborators of Killer Toxins

Science  16 Feb 2001:
Vol. 291, Issue 5507, pp. 1207
DOI: 10.1126/science.291.5507.1207a

Many gene hunters track sequences that inevitably lead to disease. Environmental health researchers seek a different quarry: variations in genes that by themselves might be harmless, but, when a person is exposed to environmental toxins, can amplify that person's risk of illness. Studies of these genes, which often code for enzymes that metabolize toxins or repair DNA damage from carcinogens, could lead to a better understanding of how the genes make people vulnerable and which individuals are at risk.

CREDIT: ILLUSTRATION: CAMERON SLAYDEN

The growing list of diseases linked to these environmental susceptibility genes includes asthma, diabetes, lead poisoning, and a lung disease caused by the metal beryllium. Many disorders involve more than one gene: Variants of two genes, for example, boost the risk of bladder cancer 10-fold in people who smoke, according to recent studies at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina.

To help find these genes and explore how they operate, toxicologists are using DNA arrays—glass chips dotted with gene sequences (Science, 28 July 2000, p. 536). For instance, Leona Samson's team at Harvard University has found that DNA-damaging chemicals known as alkylating agents turn on or off at least 400 genes in yeast cells, including “totally unexpected” genes involved in novel repair pathways, says Samson. The complete sequence of the human genome will enable scientists to do such toxicogenomic studies with cells from various human organs, notes Michael Gallo of the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School in Piscataway. “That's the real beauty of the genome. We can now start to dissect toxic responses at the molecular level,” says Gallo.

Subjects

Navigate This Article