Chemotherapy has been the main treatment for cancer for decades, yet comes with a number of serious side effects including the damage to healthy cells. This past summer, Abigail Shtekler, a sophomore student majoring in Neuroscience, spent two months at John Hopkins University to take part in a research on Targeted Radiopharmaceutical Therapy, a potential replacement for chemotherapy that can minimize the damage and maximize the treatment.
Instead of using photons, this research focuses on alpha-particle emitters and utilizes their particular characteristics of short range in tissue and high energy deposit to achieve precise targeting on cancer cells and limit the damage to normal, healthy tissues. The alpha-particles can optimize cell kill by generating DNA double-strand breaks, which allows them to have effect against radio- and chemo-resistant cancer cells.
Abigail worked in the Sgouros lab, under the supervision of the principal investigator, Dr. George Sgouros. In addition to dissecting mice, growing cells in culture dishes, helping perform endotoxin kits, she was mainly working on a mathematical model to determine the absorbed dose to cells of the treatment from an experiment. This model will also become the key to determining the relative biological efficacy(RBE) of this new treatment, which allows researchers to compare the effectiveness of this treatment to other types of treatment or therapy. The higher the RBE, the more effective the treatment is.
Photons, used in chemotherapy, has a relatively low RBE. On the effectiveness of the new treatment, Abigail notes, “Because alpha-particle emitters have such high potency and short range, we expect the efficacy to be higher than for treatments using a photon which have longer ranges in tissue and a lower potency.” To find the exact RBE, the absorbed dose of alpha-particles to each cell has to be determined first, which is exactly what Abigail had been working on over the summer. “The goal was to determine mathematically if there was a benefit to the amount of cell kill, by using the mathematical model that I was working on. For the specific experiment that was being analyzed, there were three different treatments, all using alpha particle emitters, yet some had additional treatments such as protein inhibitors that will impair the DNA’s ability to repair itself.”
The research is still ongoing, and Abigail has high hopes for the result of this research, not only because of the scientific and clinical significance of finding a better treatment for cancer, but for her personal exploration in the field as well. “This research further proved to myself how much interest I had in the sciences. It felt amazing in terms of the research and gives me hope that researchers are coming close to finding a more efficient way to treat cancer.” The result of this research will be published next year on the John Hopkins University website under the Sgouros Lab.