National Institute of Environmental Health Sciences

By: Banalata Sen

Dr. Sascha Liberti’s desire to work with the “king of DNA mismatch repair” led to her journey from Copenhagen to Research Triangle Park, North Carolina to work with Dr. Thomas Kunkel at NIEHS. “I have been reading his papers throughout my research, and I figured if I was going abroad I might as well go to the best of the best.” Liberti is but one of many scientists who travel from foreign countries to learn from NIEHS researchers.

Prior to coming to NIEHS, Liberti was a postdoctoral fellow at the University of Copenhagen, Center for Healthy Aging, where she was characterizing the human exonuclease 1 gene.  Liberti received her Ph.D. from Roskilde University, Denmark, where she studied DNA mismatch repair gene variants in cancer patients.

Liberti is a visiting fellow in the Laboratory of Structural Biology who studies exonuclease 1, a gene involved in DNA mismatch repair, using yeast as a model system. A defective mismatch repair system means that every time a cell divides and errors are introduced, the cell is incapable of repairing the errors, predisposing it to cancer or other diseases.  DNA mismatch repair also plays a critical role in aging.  As humans live longer, cells go through more cycles of replication, which creates an increased chance of error. Liberti’s research tries to understand whether mutations in DNA mismatch repair genes lead to a person developing cancer.

Exposure to environmental contaminants like cadmium compromises the mismatch repair system. According to Liberti, a molecular biologist by training, when you do DNA repair research, the environment is always at the back of your mind. All exogenous exposure to our DNA that can affect human health comes from the environment.

Liberti has spent two years at the NIEHS and hopes to continue research in her field following her return to Denmark in January. “My experience here will be crucial for my future career. My time at NIEHS has allowed me to do some cool science, and I have achieved some great results in a short amount of time. The infrastructure here has allowed that to be possible.“

Commenting on the large pool of knowledge at NIEHS, Liberti said, “You never reach a cul-de-sac in your research because there is always somebody that will help you reach the next step.” She continued, “When I have my own lab, I want to incorporate many of the research practices I observed here.” Liberti said she particularly appreciated the open door policy of her mentor, Dr. Kunkel, and his fostering of a culture of openness in sharing ideas. “For inspiring creativity,” said Liberti, “it is crucial that all ideas be heard.”