AG 555 is a potent and selective inhibitor of EGFR with IC50 value of 0.7 μM.

The epidermal growth factor receptor (EGFR) is the cell-surface receptor for epidermal growth factor and plays an important role in tumor invasion and cancer cell proliferation.

AG 555 is a potent and selective EGFR inhibitor. In HPV16-immortalized human keratinocytes, AG 555 inhibited the activation of Cdk2 and induced growth arrest at the G1 phase accompanied by 15-20% cell apoptosis [1]. AG556 arrested cells at G1/S phase by 85% and inhibited the activation of Cdk2 by phosphorylating tyrosine 15 on Cdk2 [2]. In A-498, Caki-1 and Caki-2 renal carcinoma cell lines and RT4, J82 and T24 transitional carcinoma cell lines, AG555 inhibited cell proliferation with IC50 values ranging from 3 to 16 μM in a dose-dependent way. AG555 (10-30 μM) completely inhibited cell growth [3]. In NIH/3T3 cells infected with Moloney murine leukemia virus (Mo-MuLV), AG-555 inhibited the viral DNA integrated into the host genome in acutely infected cells. While in chronically infected cells, AG-555 decreased the level of viral RNA and inhibited viral protein synthesis [4].

References:
[1].  Ben-Bassat H, Rosenbaum-Mitrani S, Hartzstark Z, et al. Inhibitors of epidermal growth factor receptor kinase and of cyclin-dependent kinase 2 activation induce growth arrest, differentiation, and apoptosis of human papilloma virus 16-immortalized human keratinocytes. Cancer Res, 1997, 57(17): 3741-3750.
[2].  Kleinberger-Doron N, Shelah N, Capone R, et al. Inhibition of Cdk2 activation by selected tyrphostins causes cell cycle arrest at late G1 and S phase. Exp Cell Res, 1998, 241(2): 340-351.
[3].  Sion-Vardy N, Vardy D, Rodeck U, et al. Antiproliferative effects of tyrosine kinase inhibitors (tyrphostins) on human bladder and renal carcinoma cells. J Surg Res, 1995, 59(6): 675-680.
[4].  Seri I, Aflalo E, Gazit A, et al. Tyrphostin AG-555 inhibits early and late stages of Moloney murine leukemia virus replication cycle. Int J Oncol, 1997, 10(6): 1185-1189.