Interview With a Scientist: Namandjé Bumpus, Drug Metabolism Maven

Medications are designed to treat diseases and make us healthier. But our bodies don’t know that. To them, medications are merely foreign molecules that need to be removed.

Before our bodies can get rid of these drug molecules, enzymes in the liver do the chemical work of preparing the molecules for removal. There are hundreds of different versions of these drug-processing enzymes. Some versions work quickly, others work slowly. In some cases, the versions you have determine how well a medication works for you, and whether you experience side effects from it.

Namandjé Bumpus Exit icon, a researcher at Johns Hopkins University School of Medicine, is interested in how human bodies respond to HIV medications. She studies the enzymes that process these drugs. Her research team discovered that a genetic variant of a liver enzyme impacts the way some people handle a particular HIV drug. This variant is found in around 80 percent of people of European descent. She describes her work in this video.

Bumpus recently presented her research to a more scientifically advanced audience at an Early Career Investigator Lecture at the National Institutes of Health. Watch her talk titled Drug Metabolism, Pharmacogenetics and the Quest to Personalize HIV Treatment and Prevention.

Dr. Bumpus’ work is supported in part by NIGMS grant R01GM103853.

Data-Mining Study Explores Health Outcomes from Common Heartburn Drugs

Results of a data-mining study suggest a link between a common heartburn drug and heart attacks. Credit: Stock image.

Scouring through anonymized health records of millions of Americans, data-mining scientists found an association between a common heartburn drug and an elevated risk for heart attacks. Their preliminary results suggest that there may be a link between the two factors.

For 60 million Americans, heartburn is a painful and common occurrence caused by stomach acid rising through the esophagus. It’s treated by drugs such as proton-pump inhibitors (PPIs) that lower acid production in the stomach. Taken by about one in every 14 Americans, PPIs, which include Nexium and Prilosec, are the most popular class of heartburn drugs.

PPIs have long been thought to be completely safe for most users. But a preliminary laboratory study published in 2013 suggested that this may not be the case. The study, led by a team of researchers at Stanford University, showed that PPIs could affect biochemical reactions outside of their regular acid suppression action that would have harmful effects on the heart. Continue reading

Genetic Discovery Could Enable More Precise Prescriptions

Prescription pad with DNA illustration on it. Credit: Jane Ades, NIH’s National Human Genome Research Institute.
New insight into the genes that affect drug responses may help doctors prescribe the medications and doses best suited for each individual. Credit: Jane Ades, NIH’s National Human Genome Research Institute.

Scientists know that variations in certain genes can affect the way a person responds to medications. New research by Wolfgang Sadee Exit icon at Ohio State University shows that drug responses also depend on previously overlooked parts of DNA—sections that regulate genes, but are not considered genes themselves. This study focused on an important enzyme abbreviated CYP2D6 that processes about one-fourth of all prescription drugs. Differences in the enzyme’s performance, which range from zilch to ultra-rapid, can dramatically alter the effectiveness and safety of certain medications. Researchers discovered two new genetic variants that impact CYP2D6 performance. One of these, located in a non-gene, regulatory region of DNA, doubles or even quadruples enzyme activity. Coupling these findings with genetic tests could help doctors better identify each patient’s CYP2D6 activity level, enabling more precise prescriptions. The findings also open up a whole new area of investigation into genetic factors that impact drug response.

This work also was funded by NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Learn more:

Ohio State University News Release Exit icon
Using Genes to Guide Prescriptions Article from Inside Life Science Series