Kinase experiment:

AZD3759 is tested at a single 1 μM concentration across each of 124 kinases from Millipore kinase panel at an ATP concentration that is within 15 μM of their corresponding apparent Km values. The detailed protocols could be obtained from Millipore. In brief, recombinant kinases are incubated within appropriate buffer containing peptide substrate and radiolabelled γ-33P-ATP together with presence or absence of required inhibitor concentration. The reaction is initiated by adding ATP/Mg2+ mix. After incubation for 40 minutes at room temperature, the reaction is stopped by adding 3% phosphoric acid solution. A portion of reaction mix is spotted onto P30 filtermat to trap peptide, and washed three times for 5 minutes with phosphoric acid to remove non-specific γ-33P-ATP. The phosphorylated substrate is then measured by scintillation counting, which determined the level of kinase activity inhibition compared to control reactions[1].

Cell experiment:

Cell proliferation assay is determined by MTS methods. Briefly, cells are seeded in 96-well plates (at a density to allow for logarithmic growth during the 72-hour assay) and incubated overnight at 37℃ and 5% CO2. Cells are then exposed to concentrations of compounds (e.g., AZD3759) ranging from 30 mM to 0.3μM for 72 hours. For the MTS endpoint, cell proliferation is measured by the CellTiter AQueous Non-Radioactive Cell Proliferation Assay reagent. Absorbance is measured with a Tecan Ultra instrument. Predose measurements are made, and concentration needed to reduce the growth of treated cells to half that of untreated cells (GI50) values are determined using absorbance readings[1].

Animal experiment:

Rats[1] Male Han Wistar rats are orally dosed with the AZD3759 at 2 mg/kg in 1% methylcellulose. At 0.25, 0.5, 1, 2, 4 and 7 hour post-dose, cerebral spinal fluid (CSF) is collected from cisterna magna, and blood samples (>60 μL/time point/each site) are collected via cardiac puncture, into separate EDTA coagulated tubes, and then immediately diluted with 3-fold volume of water. Brain tissue is harvested and homogenized in 3x volume of 100 mM phosphate buffered saline (pH7.4). All samples are stored at -70℃ prior to LC/MS/MS analysis.

AZD3759 is a potent and oral active inhibitor of EGFR (IC50= 7.0-7.7 nM) with antineoplastic activity.

EGFR (epidermal growth factor receptor) is a cell-surface receptor tyrosine kinase. The receptor activation leads to dimerization and tyrosine autophosphorylation. It induces a cascade of downstream cellular responses such as modification in gene expression, cell proliferation and cytoskeletal rearrangement etc.

AZD3759 shows equally potent inhibitory effect on cell phosphorylation or proliferation in EGFR-activating mutant cell lines (PC-9 and H3255) in the range of 7.0–7.7nM. In cellular phosphorylation assays, AZD3759 also exhibits 9-fold inhibition selectivity in EGFR-activating

mutant cell lines over EGFR wild-type cell lines (H838). [1]

In brain metastasis mouse model, AZD3759 demonstrates prominent antitumor efficacy in a dose dependent manner (~78% tumor growth inhibition at 7.5 mg/kg qd and tumor regression at 15 mg/kg qd, respectively, 4 weeks after treatment, with

Reference:
[1].Zeng Q, Wang J, Cheng Z et al. Discovery and Evaluation of Clinical Candidate AZD3759, a Potent, Oral Active, Central Nervous System-Penetrant, Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor. J Med Chem. 2015 Oct 22;58(20):8200-15