Washington, Feb 20 : The famous remedy for curing a common cold - chicken soup - might also be of great use in the detection of an aggressive form of breast cancer, say researchers.
The study, conducted by researchers at the National Institute of Standards and Technology (NIST), the National Cancer Institute (NCI) and the scientific research firm SAIC, showed how chicken antibodies may help improve diagnose HER2 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 cancers have multiple copies of the gene, resulting in the overproduction of a HER2-encoded protein (called HER2) that stimulates tumors to be particularly fast growing and difficult to treat in a subset of breast cancer patients.
Patients with that form of breast cancer can be treated with a monoclonal antibody called trastuzumab that targets and inhibits the growth of tumor cells with higher-than-normal levels of the HER2 protein.
But because the treatment can have adverse side effects, it's important to screen for those patients who would benefit from it by testing them for one or both of the two relevant biomarkers: the amplified HER2 gene or its over expressed HER2 protein.
Unfortunately, the existing tests for these biomarkers can yield a significant number of false positives, resulting in some women getting a somewhat risky and expensive treatment that can't help them.
In a paper in the International Journal of Cancer, the research team found that chicken immunoglobulin Y (IgY) antibody created against the HER2 protein could be tagged with quantum dot (tiny, intense and tunable sources of colorful light) to more reliably detect the HER2 biomarker than the existing diagnostic tests using mammalian antibodies tagged with conventional fluorescent dyes.
Overall, the improvement in sensitivity to the HER2 biomarker was about 40-50 percent.
The increased sensitivity of the HER2 quantum dot-based quantitative bioimaging system stems from the broad genetic differences between avian and human species. The chicken IgY antibody to HER2 reacts strongly with the target protein while ignoring other human proteins that can interfere with current diagnostic tests.