Kinase experiment:

In the in vitro kinase assays, 2.4 ng/μL EGFR protein is mixed with 32 ng/μL Crk in 25 μL kinase reaction buffer containing 1 μM cold ATP and 1 μCi32P-γ-ATP. The mix is incubated with Icotinib at 0, 0.5, 2.5, 12.5 or 62.5 nM on ice for 10 min followed by incubation at 30℃ for 20 min. After quenching with SDS sample bufferat 100℃ for 4 min, the protein mix is resolved by electrophoresis in a 10% SDS-PAGE gel. The dried gel is then exposed to detect radioactivity. Quantification is performed by software[1].

Cell experiment:

Cells (1000/well) are seeded into 96-well plates in RPMI-1640 medium containing 10% FBS and grown in a 5% CO2 incubator at 37℃. After 24 h, cells are treated with Icotinib at 0, 0.78, 1.56, 3.125, 6.25, 12.5 or 25 μM for 96 h. Cell proliferation is calculated by subtracting the mean absorbance value on day 0 from the mean absorbance value on day 4[1].

Animal experiment:

Mice: The effect of three doses of Icotinib (30, 60, and 120 mg/kg/dose p.o. qd) on antitumor activity and survival is determined in mice bearing A431, A549, H460 and HCT8 tumor xenografts. Taxol (30 mg/kg/dose i.p. once a week) is employed in these experiments as a positive control group[1].

Icotinib is a potent and specific EGFR (epidermal growth factor receptor) tyrosine kinase inhibitor (IC50 = 5 nM) [1]

EGFR are family of receptor tyrosine kinase that is a transmembrane protein involved in the regulation of cell proliferation, motility and apoptosis. EGFR are expressed in various human cancer types, including breast, head & neck, NSCLC (non-small cell lung cancer) and ovarian caners. [1]

In human epidermoid carcinoma A431 cell line, Icotinib inhibited EGF-induced EGFR phosphorylation in a dose-dependent manner. Icotinib inhibited tyrosine phosphorylation of a variety of intracellular proteins. [1]

In different types of tumor xenograft mice models, Icotinib inhibited tumor growth in a dose-dependent manner without pronounced adverse effect in body weight loss and toxicity signs. In a randomized, double-blind, Gefitinib as control and multi-center phase III trial, Icotinib demonstrated efficacy on NSCLC in advanced stage. [1]

Reference:
[1] Tan F, Shen X, Wang D, Xie G, Zhang X, Ding L, Hu Y, He W, Wang Y, Wang Y.  Icotinib (BPI-2009H), a novel EGFR tyrosine kinase inhibitor, displays potent efficacy in preclinical studies.  Lung Cancer. 2012 May;76(2):177-82.