For Research Use Only

 

Summary:

Polyclonal growth factors e.g. the epidermal growth factor (EGF) have been recognized as important determinants in the regulation of cellular proliferation and differentiation as shown in cell culture. EGF mediates its effects through receptors. The EGF-receptor (EGF-R) is a glycoprotein of 170,000 Dalton. It consists of an extra cellular domain for EGF binding, a transmembrane domain for signal transduction and an intracellular domain with tyrosine-kinase activity. Binding of EGF leads to a Ca2+ release by activation of Calmodulindependent enzymes.

Overexpression or amplification of EGF-R in breast cancer is associated with autonomous tumor growth and poor clinical prognosis.

The most widely used method of receptor identification has been a radioligand - assay with 125I-labelled EGF. The advantage of the radioligand assay is the measurement of native receptor. On the other hand, this test system is combined with a lot of disadvantages (e.g. great amount of tumor material, radioactivity, poor reproducibility, time consuming calculation). In the offered test system EGF-R is determined by specific antibodies. This immunoassay shows good reproducibility, small sample volume, and is easy to calculate. The sensitivity for h EGF-R in ELISA - technique is 0.4 fMol/ml.

Literature References:

Roth HJ, Seikel I, Schmidt B, Klöppinger M, Kasper U, Armbruster FP (1994) Is it necessary for a Quantitative EGF-Receptor Assay to Detect the Ligand Binding Site? Comparison of Methods: Radioligand Binding Assay (RLBA) vs IEMA Ligand Binding Site vs IEMA Non-Ligand Binding Site, Klin Lab 40:1025-32

Roth HJ, Seikel I, Schmidt B, Klöppinger M, Kasper U, Armbruster FP (1994) Muß ein quantitativer EGF-R-Assay die Ligandenbindungsstelle erkennen? Methodenvergleich: Radioligandenbindungsassay (RLBA) vs IEMA Ligandenbindungsstelle vs IEMA Nicht-Ligandenbindungsstelle, Klin Lab 40:1017-24

Manneck HE, Steinhilber G, Pollow K, Roos W, Ruppert J, Armbruster FP (1993) Enzyme-linked Immunosorbent Assay for the Determination of Epidermal Growth Factor Receptor, Klin Lab 39: 177-82