Atomic force microscopy (AFM) techniques were used to measure the adhesion forces between the receptors on breast cancer cells specific to human luteinizing hormone-releasing hormone (LHRH) peptides and antibodies specific to the EphA2 receptor. The adhesion forces between LHRH-coated AFM tips and human MDA-MB-231 cells (breast cancer cells) were shown to be about five times greater than those between LHRH-coated AFM tips and normal Hs578Bst breast cells. Similarly, those between EphA2 antibody-coated AFM tips and breast cancer cells were over five times greater than those between EphA2 antibody-coated AFM tips and normal breast cells. The results suggest that AFM can be used for the detection of breast cancer cells in biopsies. The implications of the results are also discussed for the early detection and localized treatment of cancer.

This paper presents the results of atomic force microscope (AFM) measurements of the adhesion force between MDA-MB-231 breast cancer cells and anti-EphA2 antibody-coated AFM tips. As a control, the adhesive interactions are measured between Hs578Bst normal breast cells and anti-EphA2 antibody-coated AFM tips. The measurements show conclusively that the adhesive forces to breast cancer cells are over five times greater than those to normal breast cells. The increase is attributed largely to the interactions between anti-EphA2 antibody and overexpressed EphA2 receptors that are revealed by the staining of receptor-ligand interactions. The implications of the results are discussed for the localized targeting and treatment of cancer with antibody-conjugated nanoparticles.