In vitro activity: NSC 228155 promotes transactivation of several RTKs, including ErbB2 and ErbB3, Insulin R and IGF-1 R receptors in the cells. It stimulates dimerization of sEGFR domain II. NSC 228155 can rapidly move across cell membranes and disperse within both cytoplasmic and nuclear compartments. It rapidly generates hydrogen peroxide within cells. NSC 228155 is also a potent inhibitor of KIX-KID interaction(IC50 = 0.36 μM), but it is not particularly selective against CREB-mediated gene transcription in HEK 293T cells.

Cell Assay: MDA MB468 cells serum-starved overnight are pre-incubated (or not) with 10 μM AG1478 or 2 μM PD 153035 for 90 min and then, where indicated, incubated with 100 μM NSC 228155 or CN 009543V or 150 ng/ml EGF or vehicle (0.2% DMSO) for 15 min. Proteins are blotted to nitrocellulose membrane and analyzed with biotinylated anti-pTyr P100, anti-pEGFR Y1068 and anti-EGFR (epitope in cytoplasmic region) antibodies.