February 28, 2008

Gene Expression Differences Affect Drug Response

THURSDAY, Feb. 28 (HealthDay News) -- People of European and African ancestry have differences in gene expression levels that affect how they respond to certain kinds of drugs and fight off specific types of infections, says a new U.S. study.

Researchers studied 30 white families from Utah and 30 Yoruban families from Nigeria, and found significant variations in nearly 5 percent of the 9,156 genes they analyzed. The findings were published online in the American Journal of Human Genetics and are expected to be published in the March 7 print issue of the journal.

"Our primary interest is the genes that regulate how people respond to medicines, such as cancer chemotherapy," senior study author Eileen Dolan, a professor of medicine at the University of Chicago, said in a prepared statement. "We want to understand why different populations experience different degrees of toxicity when taking certain drugs and learn how to predict who might be most at risk for drug side effects."

In this study, Dolan and her colleagues found expected variations in immune system response to microbial invaders. Previous studies have shown that black Americans may be more susceptible than whites to infection by certain kinds of bacteria, such as the kind that cause periodontitis.

But they also made some unexpected findings of major differences in expression levels of genes involved in a communication system that governs basic cellular activities and coordinates cell actions.

"Population differences in gene expression have only recently begun to be investigated. We believe they play a significant role in susceptibility to disease and in regulating drug response. Our current research focuses on how these genetic and expression differences play a role in sensitivity to adverse effects associated with chemotherapy," Dolan said.

Learning more about how a person's genetics affects their response to drugs may help lead to improvements in treatment.

More information

The U.S. National Institute of General Medical Sciences has more about genes and medicine.

-- Robert Preidt
SOURCE: University of Chicago Medical Center, news release, Feb. 28, 2008
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