According to the American Cancer Society, there were an estimated 1,762,450 new cancer cases and 606,880 estimated cancer deaths in 2019. As the successful treatment of cancer is often associated with early detection, researchers around the world are focusing efforts on developing novel diagnostics that target biomarkers such as enzymes that tend to be overexpressed in individuals where diseases like cancer are present. One such enzyme is thioredoxin reductase.
Recent research from a team of collaborators at Portland State and Oregon Health and Science University describes a new tool for detecting thioredoxin reductase, which is associated with cancers, including melanoma, and other diseases such as Parkinson’s.
According to Tendai Mafireyi, a Ph.D. candidate in chemistry professor Rob Strongin's lab, the enzyme thioredoxin reductase addresses oxidative stress within cells. It is also abundant in cells where certain diseases are present, making the enzyme a potential target for detecting disease.
Working with melanoma researchers, including Pamela Cassidy, at OHSU, Mafireyi developed a novel selenium-based dye that changes color when it interacts with thioredoxin reductase. As Mafireyi noted, the research team's work shows that his dye is better at detecting thioredoxin reductase than sulfur-based compounds currently available on the market.
"What we found," Mafireyi said, "is that our probe is more selective for the enzyme and has a quicker response than the other options we tested. And what's unique about it is that it is Selenium-based, which gives it a greater affinity and better reaction with thioredoxin reductase."
In the Strongin lab, researchers focus on developing fluorescent compounds designed to detect specific disease biomarkers. According to Professor Strongin, the dyes the team makes function like a pH test, only they indicate biological molecules' presence. The long-term goal is to incorporate the dyes into non-invasive diagnostic tools for detecting certain diseases such as melanoma.
Mafireyi's research is a part of his dissertation work at Portland State. According to Strongin, Mafireyi’s probe could help address unanswered questions about thioredoxin reductase, such as why there are some instances of melanoma where the enzyme is not present at elevated levels.