From the simple to the complex:

Dalhousie Medical School scientists use yeast as a key to unlock the secrets of cancer

Bakers’ yeast is a simple organism – yet the genetic and cellular processes that make a spoonful of yeast in warm sugar water blossom into a frothy mass are the very same that tell human cells to start dividing. In fact, senior Dalhousie Medical School researchers Drs. Gerry Johnston and Rick Singer have been studying yeast as a model for cancer for more than 30 years. Their studies have revealed many of the processes that prompt cells to switch from a normal, non-dividing state, to a state of rapid cell division.

“Looking at something as simple as yeast has allowed us to see how cells make this critical transition,” says Dr. Singer, professor in the Department of Biochemistry & Molecular Biology. “From discovering the mechanism, we’ve been able to show that the same processes are important in mammalian cells.”

By working with yeast, Drs. Johnston and Singer are building a picture of the genetic changes and molecular events that take place during the earliest stages of cell division – a process that is important for cancer development.

“We have about 100 trillion cells in our bodies, and most of them are not dividing,” says Dr. Johnston, professor in the Department of Microbiology & Immunology and Associate Dean of Research at Dalhousie Medical School. “When cells start dividing when they’re not supposed to – that is, dividing out of control – we end up with cancer. Finding the signs that this has started to happen could open the door to new ways of detecting cancer in its early, most curable, stages.” He adds that in-depth knowledge of the complex origins of cancer will lead to more sophisticated and effective cancer therapies in the future.

Yeast is such an important model for human biology that thousands of scientists now work in the field. “Much of what we understand about cells such as neurons comes from yeast, even the first enzymes were discovered through yeast,” Dr. Johnston says. “Here at Dalhousie, we’re learning more than ever, with new robotic technology that allows us to do experiments in weeks that would otherwise take years.”