AG 825 is a selective inhibitor of ErbB2 with IC50 values of 0.15 and 19 μM for ErbB2 and ErbB1 respectively [1].
Receptor tyrosine-protein kinase erbB-2 is a member of the human epidermal growth factor receptor family and promotes cell proliferation.
AG 825 is a selective ErbB2 inhibitor. AG825 inhibited autophosphorylation of HER2, HER1-2 and HER1 with IC50 values of 0.15, 0.35 and 19 μM, respectively [1]. In non-small cell lung cancer (NSCLC) cell lines expressing high-p185neu, the HER-2/neu gene product, AG825 significantly increased the chemosensitivities. However, AG825 with high concentrations inhibited the drug-induced G2 arrest and the activation of phosphorylated p34cdc2 [2]. In androgen-independent prostate cancer (PCa) cell lines C4 and C4-2, AG825 was toxic in a dose- and time-dependent way and inhibited phosphoactivation of HER-2/neu and its down-regulation. Also, AG825 induced an imbalance between p38 mitogen-activated protein kinase activation and extracellular signal-regulated kinase 1/2, which then led to p38-dependent apoptosis [3].
References:
[1]. Osherov N, Gazit A, Gilon C, et al. Selective inhibition of the epidermal growth factor and HER2/neu receptors by tyrphostins. J Biol Chem, 1993, 268(15): 11134-11142.
[2]. Tsai CM, Levitzki A, Wu LH, et al. Enhancement of chemosensitivity by tyrphostin AG825 in high-p185(neu) expressing non-small cell lung cancer cells. Cancer Res, 1996, 56(5): 1068-1074.
[3]. Murillo H, Schmidt LJ, Tindall DJ. Tyrphostin AG825 triggers p38 mitogen-activated protein kinase-dependent apoptosis in androgen-independent prostate cancer cells C4 and C4-2. Cancer Res, 2001, 61(20): 7408-7412.