Receptor tyrosine kinase signaling pathway analysis for diagnosis and therapy

A method of profiling one or more components of a signaling pathway comprising one or more cell surface receptors, cell surface receptor complexes, signaling complexes, or effector proteins, the method comprising the steps of:

• providing for each of the one or more components at least one cleaving probe specific for a first antigenic determinant on said one or more components and having a cleavage-inducing moiety with an effective proximity;
• providing one or more binding compounds specific for a second antigenic determinant of each of the one or more components, wherein each cleaving probe and binding component comprises an antibody or antigen binding fragment of an antibody, such that each binding compound has one or more molecular tags each attached thereto by a cleavable linkage, and such that the one or more molecular tags attached to different binding compounds have different separation characteristics so that upon separation molecular tags from different binding compounds form distinct peaks in a separation profile;
• mixing the cleaving probes, the binding compounds, and the one or more components such that cleaving probes specifically bind to the first antigenic determinants and binding compounds specifically bind to the second antigenic determinants and such that cleavable linkages of the binding compounds are within the effective proximity of cleavage-inducing moieties of the cleaving probes so that molecular tags are released;
• and
• separating and identifying the released molecular tags to determine the presence or absence or the amount of the one or more components of the signaling pathway.