In high school classrooms, cell division is taught as a precisely choreographed series of steps: When it’s time for a cell to divide, chromosomes are condensed, dragged into an orderly line, and then split evenly between the two new cells.
Kristin Turner’s research has shown that in cancer, cell division becomes far, far more complicated — in part because of a type of circular DNA called extrachromosomal DNA that she has studied for the past seven years.
Turner, who was a first-generation college student from southeast Colorado, loved the lessons on Mendelian genetics in her seventh grade biology class and found herself fascinated by forensics shows in the late 1990s.
“Looking for clues and being an investigator really intrigued me,” Turner said.
Now, Turner works at Boundless Bio, a biotech startup in La Jolla, California that is trying to understand and target extrachromosomal DNA. The chair of the company’s scientific advisory board is Paul Mischel, who was Turner’s post-doctoral advisor at Ludwig Institute for Cancer Research.
Extrachromosomal DNA, or ecDNA, is genetic material that doesn’t form into those X-like shapes when a cell divides; instead, it exists as a circle — and unlike normal chromosomes, those cells can be distributed unevenly after a cell divides.
In cancerous tumors, each cell can have different genetic material, which makes it very difficult to find one drug that will kill every cancer cell. The irregular division of ecDNA may be one key reason why this genetic collage exists — and why some cancers seem impervious to targeted treatments.
“Looking for clues and being an investigator really intrigued me.”
Boundless is still a pre-clinical company, so it’s not yet clear if it will be able to develop drugs that can treat human cancers. But for Turner, that’s part of Boundless Bio’s appeal. “Because it’s a brand new company, and we’re still learning about ecDNA, I’m still able to do a lot of basic science — and we’re making phenomenal, underlying discoveries about ecDNA here,” she said.
“My lifelong dream is to have my research make a difference for patients,” Turner said.
— Kate Sheridan
