Bioethics Blogs

Creative Minds: Bacteria, Gene Swaps, and Human Cancer

Julie Dunning Hotopp

When Julie Dunning Hotopp was a post-doctoral fellow in the early 2000s, bacteria were known for swapping bits of their DNA with other bacteria, a strategy known as lateral gene transfer. But the offloading of genes from bacteria into multicellular organisms was thought to be rare, with limited evidence that a bacterial genus called Wolbachia, which invades the cells of other organisms and takes up permanent residence, had passed off some of its DNA onto a species of beetle and a parasitic worm. Dunning Hotopp wondered whether lateral gene transfer might be a more common phenomenon than the evidence showed.

She and her colleagues soon discovered that Wolbachia had engaged in widespread lateral gene transfer with eight species of insects and nematode worms, possibly passing on genes and traits to their invertebrate hosts [1]. This important discovery put Dunning Hotopp on a research trail that now has taken a sharp turn toward human cancer and earned her a 2015 NIH Director’s Transformative Research Award. This NIH award supports exceptionally innovative research projects that are inherently risky and untested but have the potential to change fundamental research paradigms in areas such as cancer and throughout the biomedical sciences.

Unlike insects and worms, people don’t harbor lots of bacteria in their cells. But the human body does play host to a diverse array of microbes, collectively known as the human microbiome. Dunning Hotopp, now an associate professor of microbiology and immunology at the University of Maryland School of Medicine, Baltimore, began wondering several years ago while pursuing this new research trail whether it was possible that bacterial DNA might also make its way into the human genome—probably not into the germline (the part that gets passed to future generations), but into various cells of the body (so-called somatic cells).

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.