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 buffer at 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 Hydrochloride is a potent and highly selective inhibitor of epidermal growth factor receptor tyrosine kinases (EGFR-TKI) with IC50 value of 5 nM.
EGFR is an oncogenic driver which is expressed on the cell surface of normal cells and cancer cells [1], and patients with somatic mutations, particularly an exon 19 deletion or exon 21 L858R mutation, within the tyrosine kinase domain have activating mutations that lead to unchecked cell proliferation.[2] Overexpression of EGFR caused inappropriate activation of the anti-apoptotic Ras signaling pathway, found in many different types of cancer.[3]
Icotinib is a quinazoline derivative that binds reversibly to the ATP binding site of the EGFR protein, preventing completion of the signal transduction cascade.[4] Icotinib inhibited the intracellular phosphorylation of tyrosine kinase(TK) associated with the epidermal growth factor receptor (EGFR).[5]
Icotinib is indicated for the treatment for EGFR mutation-positive, advanced or metastatic non-small cell lung cancer (NSCLC) as a second-line or third-line treatment, for patients who have failed at least one prior treatment with platinum-based chemotherapy.[6]
References:
1.A Douglas Laird,and Julie M Cherrington. Small molecule tyrosine kinase inhibitors: clinical development of anticancer agents. 2003, 12(1): 51-64.
2.Raymond E, Faivre S, Armand JP: Epidermal growth factor receptor tyrosine kinase as a target for anticancer therapy. Drugs. 2000;60 Suppl 1:15-23.
3.Sordella,R. "Gefitinib-Sensitizing EGFR Mutations in Lung Cancer Activate Anti-Apoptotic Pathways". Science ,2004, 305 (5687): 1163-1167.
4.Bulgaru AM. et al. Erlotinib (Tarceva): a promising drug targeting epidermal growth factor receptor tyrosine kinase. Expert Rev Anticancer Ther. 2003 Jun;3(3):269-79.
5.Dudek AZ.et al. Skin rash and bronchoalveolar histology correlates with clinical benefit in patients treated with gefitinib as a therapy for previously treated advanced or metastatic non-small cell lung cancer. Lung Cancer. 2006, 51(1):89-96.
6.C Delbaldo, S Faivre, E Raymond. Les inhibiteurs des récepteurs de l'Epidermal Growth Factor (EGF) Epidermal growth factor inhibitors. La Revue de Médecine Interne. 2003,24(6): 372–383.