Tiny gold particles can help doctors detect tumor cells circulating in the blood of patients with head and neck cancer, researchers at Emory and Georgia Tech have found.
The detection of circulating tumor cells (CTCs) is an emerging technique that can allow oncologists to monitor patients with cancer for metastasis or to evaluate the progress of their treatment. The gold particles, which are embedded with dyes allowing their detection by laser spectroscopy, could enhance this technique's specificity by reducing the number of false positives.
The results are published online in the journal Cancer Research.
One challenge with detecting CTCs is separating out signals from white blood cells, which are similarly sized as tumor cells and can stick to the same antibodies normally used to identify tumor cells. Commercially available devices trap CTCs using antibody-coated magnetic beads, and technicians must stain the trapped cells with several antibodies to avoid falsely identifying white blood cells as tumor cells.
Emory and Georgia Tech researchers show that polymer-coated and dye-studded gold particles, directly linked to a growth factor peptide rather than an antibody, can detect circulating tumor cells in the blood of patients with head and neck cancer.
The key technological advance here is our finding that polymer-coated gold nanoparticles that are conjugated with low molecular weight peptides such as EGF are much less sticky than particles conjugated to whole antibodies, says Shuming Nie, PhD, a professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. This effect has led to a major improvement in discriminating tumor cells from non-tumor cells in the blood.
The particles are linked to EGF (epithelial growth factor), whose counterpart EGFR (epithelial growth factor receptor) is over-produced on the surfaces of several types of tumor cells.
|Contact: Holly Korschun|