The growth factor receptor bound protein 2 (Grb2) is an intracellular adaptor protein. By its SH2 domain binding to the specific pTyr containing motif on the activated EGFR, Grb2 triggers the downstream activation of mitogenic Ras pathways which have been implicated in the etiology of certain breast cancers. So Grb2-SH2 has been recognized as an excellent target for the antitumor drug design. In this article, the re-cent progress of Grb2-SH2 inhibitors is reviewed, focused on the strategy to overcome the problems of the high charge and the low bioavailability endowed by the essential phosphotyrosine and the peptidic nature, respectively. The systematic structure-activity relationship study and the rational structural optimization were achieved based on the ligand-protein interaction to improve the potency and simplify the molecular structure, providing useful information for the future development of phosphotyrosine-mediated SH2 sig-naling inhibitors into antitumor agents.

Key words: phosphotyrosine, Grb2-SH2 inhibitor, structure-activity relationship, mitogenic ras pathway, anti-tumor drug