In attempt to identify biological markers, or biomarkers, that can signal the presence of cancer and help oncologists determine the best course of therapy when cancer is present, teams of investigators are scouring stored tissue samples obtained from thousands of cancer patients.
Such studies are laborious and suffer from limited sensitivity, making it difficult to quantify rare biomarkers and develop data that might reveal a correlation among specific patterns of protein expression and specific types of cancer.
Researchers at the University of Toronto may have a solution to this problem, one that uses quantum dots to quantify protein expression in tumors in an accurate and sensitive manner and is amenable for use in high-throughput assays of clinical tissue samples. The investigators, led by Warren Chan, Ph.D., have published the specifics of this new system in the journal Nano Letters.
The breakthrough in sensitivity and accuracy comes from two parallel developments. First, Chan and his colleagues labeled biomarker detection molecules with quantum dots. In the reported study, the investigators used antibodies that bind to specific cancer biomarkers, but they could have used aptamers or peptides, such as those being developed as part of the National Cancer Institute’s Alliance for Nanotechnology in Cancer program. Quantum dots generate a much more powerful fluorescent signal than typical fluorescent dyes, which provides a large increase in sensitivity compared to other methods. Quantum dots are also available in multiple colors, allowing the investigators to tag each antibody with a uniquely colored quantum dot.