Chasing Circles to Cure Cancer

Assistant professor Eunhee Yi is exploring how extrachromosomal circular DNA drives cancer progression and drug resistance

By T. Lee | Sep 12, 2025 |

Article Highlights

Yi studies extrachromosomal DNA, or ecDNA, to understand therapy-resistant cancers.
She was recently awarded a grant from the Elsa U. Pardee Foundation to support her research.
Her team is developing models to track ecDNA formation and identify drugs that specifically target ecDNA-containing cancer cells.

Eunhee Yi poses in her lab wearing a white lab coat. — Assistant professor Eunhee Yi is investigating how extrachromosomal DNA shapes cancer progression. Credit: T. Lee

Eunhee Yi never expected to become a scientist.

Born and raised in South Korea, she knew that only students who mapped out their career paths early on and earned top grades had a real chance of being admitted to medical school. Naturally, Yi leaned into her passion and pursued a career in art.

But even while art inspired her creativity, biology came naturally. Though she struggled in other subjects, she consistently ranked near the top of her class in biology. Following her teachers’ advice, she decided to major in the subject in college.

Her curiosity deepened during her undergraduate summers as a research technician in a natural product chemistry lab, where she helped validate compounds that inhibited cancer-promoting genes.

“The fact that we can discover potential future treatment options in the lab greatly excites me,” said Yi, who went on to earn a Ph.D. in biomedical sciences from Seoul National University. “These experiences helped me find my enthusiasm for pursuing a career in cancer research.”

Now an assistant professor in Michigan State University’s Department of Physiology, Yi recently received a grant from the Elsa U. Pardee Foundation to investigate how cancer cells evade treatment using extrachromosomal DNA, or ecDNA.

“Cancer cells gain more copies of oncogenes that cause or advance cancers during treatment,” Yi explained. “The most prevalent way that cancer cells use to gain more oncogene copies is by amplifying genes as circular DNA outside chromosomes, and we call it extrachromosomal DNA.”

Eunhee Yi and members of her lab poses in white lab coats in a lab. — Yi and her lab are developing new models to track ecDNA and identify drugs that can selectively target cancer cells containing it. Credit: T. Lee

Yi’s current research focuses on melanoma, an aggressive form of skin cancer. With support from the Pardee Foundation, her lab is developing a longitudinal model system to track ecDNA formation and perform multi-omics analysis to understand how it drives drug resistance. Additionally, her lab aims to identify drugs that specifically target ecDNA-containing cancer cells.

“This grant will help us understand ecDNA generation and its role in treatment resistance,” Yi said. “It’s an emerging area in cancer research, and the insights we gain could open the door to new therapies.”

The grant also offers important career opportunities, she added.

“This award will help me generate preliminary data that will be crucial to obtaining future major research grants such as an R01,” Yi said. “The research outcomes supported by this award will also help me build a reputation as an independent researcher in the cancer research field.”

Her lab is already developing new models to track ecDNA and identify drugs that can selectively target cancer cells containing it. Yi sees a future where ecDNA research could lead to innovative therapies across multiple cancer types and reshape treatment approaches.

“We will keep exploring ecDNA’s roles in different aspects of cancer progression,” she said. “We will further validate ecDNA’s role in treatment resistance in other cancer types. Another area we are interested in is studying ecDNA’s role in the reprogramming of cancer metabolism. EcDNA’s role in reshaping cell-to-cell communication is also an unexplored area in which my team wants to go.”

Flexing the artistic talent that’s always been part of her repertoire, Yi’s lab logo is more than meets the eye. “As a whole, these two Korean characters make my last name Yi in Korean ‘이’,” she explained. “Scientifically, the circle on the left indicates circular DNA (ecDNA) and the stick on the right indicates linear chromosomal DNA. These collectively show my team’s research interest in the differential regulation of circular and linear DNA in cancers.” Courtesy graphic

Yi’s work places her at the center of a rapidly growing area in cancer research that she’s eager to help shape.

“Extrachromosomal DNA was once a very small field, but it’s expanding fast,” she said. “This year’s world’s largest cancer conference had three dedicated sessions on it. Being in the middle of this growth, I feel both challenged and excited to contribute.”

Yi pushes the boundaries of cancer biology while balancing a busy family life with her husband and two young daughters, ages 1 and 6. She still finds time to express her creativity for art through knitting and a newly discovered passion for paint-by-numbers projects, including a giant Eiffel Tower piece.

“I like starting things I can finish,” she said, adding that the Eiffel Tower will be completed eventually. “Unfinished work really makes me feel stressful.”

Yet, it’s a perspective that has carried into her approach to succeed in science, too.

“Most days in research are experiencing failure,” she said. “But what if I finish this project? There will be a better idea to cure cancer, to move the research forward. I try to think about that.”