ELISA for quantitation of the extracellular domain of p185 super(HER2) in biological fluids

The HER2/neu proto-oncogene encodes a receptor that belong to the tyrosine-specific protein kinase family. Amplification of the HER2 gene in patients with breast and ovarian cancer has been shown to predict poorer survival rates. In order to understand the role of HER2 in malignant and normal cells, it is necessary to devise assays that can quantitate expression levels of the HER2 gene product (p185 super(HER2)) in production samples, biopsy specimens and biological fluids. We have developed a simple, quantitative ELISA that uses two monoclonal antibodies directed against the extracellular domain of the HER2 gene product, p185 super(HER2) (HER2 ECD). This assay should be useful for quantitating low levels of circulating rHER2 ECD in animals in which rHER2 ECD is being used as antigen for immunotherapy and in patients which "shed" receptor.