Single-walled nanotubes—cylinders of carbon about a nanometer in diameter—have been highly touted for potential applications such as ultrastrong fibers, electrical wires in molecular devices, or hydrogen storage components for fuel cells. Thanks to a new development by researchers at the National Institute of Standards and Technology (NIST) and five partners, you can add one more application to the list: detection and destruction of an aggressive form of breast cancer.
HER2 is one of a family of genes that help regulate the growth and proliferation of human cells. Normal cells have two copies of HER2, but about 20 to 25 percent of breast cancer cells have multiple copies of the gene, resulting in the overproduction of a HER2-encoded protein (called HER2 and designated in Roman type versus italics for the gene) that is associated with particularly fast growing and difficult to treat tumors. About 40,000 women in the United States are diagnosed annually with this form of breast cancer.
In a recently published paper in BMC Cancer,* the NIST-led research team bonded an antibody that has been created to attack the HER2 protein, chicken immunoglobulin Y (IgY), to short nanotubes (about 90 nanometers long, or 5,000 times shorter than an amoeba). Both halves of the special combination—the antibody and the nanotube—have critical roles to play in selectively hunting down the HER2 tumor cells and eliminating them.
First, the broad genetic differences between avian and human species means that the chicken IgY antibody to HER2 reacts strongly with the target protein expressed on tumor cells while ignoring normal cells with other human proteins. The carbon nanotubes attached to the antibodies also become linked to the HER2 tumors.