[1]. You WK, et al. VEGF and c-Met blockade amplify angiogenesis inhibition in pancreatic islet cancer. Cancer Res, 2011, 71(14), 4758-4768.
[2]. Torres KE, et al. Activated MET is a molecular prognosticator and potential therapeutic target for malignant peripheral nerve sheath tumors. Clin Cancer Res, 2011, 17(12), 3943-3955.
[3]. Yakes FM, et al. Cabozantinib (XL184), a novel MET and VEGFR2 inhibitor, simultaneously suppresses metastasis, angiogenesis, and tumor growth. Mol Cancer Ther, 2011, 10(12), 2298-2308
Sunitinib Malate (formerly also known as SU11248 Malate; trade nameSutent)) is a potent, orally bioavailable and multi-targeted RTK (receptor tyrosine kinase) inhibitor with potent anticancer activities. It inhibits VEGFR2 (Flk-1) and PDGFRβ with IC50s of 80 nM and 2 nM in cell-free assays, and also inhibits c-Kit. It was approved by the FDA for the treatment of renal cell carcinoma and imatinib-resistant gastrointestinal stromal tumor on January 26, 2006. Sunitinib Malate is the malate salt of an indolinone-based tyrosine kinase inhibitor with potential antineoplastic activity. Sunitinib blocks the tyrosine kinase activities of VEGFR2, PDGFRb, and c-kit, thereby inhibiting angiogenesis and cell proliferation. [1]
激酶实验
IC50 values for Sunitinib against VEGFR2 (Flk-1) and PDGFRβ are determined using glutathione S-transferasefusion proteins containing the complete cytoplasmic domain of the RTK. Biochemical tyrosine kinase assays to quantitate the trans-phosphorylation activity of VEGFR2 (Flk-1) and PDGFRβ are performed in 96-well microtiter plates precoated (20 μg/well in PBS; incubated overnight at 4 °C) with the peptide substrate poly-Glu,Tyr (4:1). Excess protein binding sites are blocked with the addition of 1-5% (w/v) BSA in PBS. Purified GST-fusion proteins are produced in baculovirus-infected insect cells. GST-VEGFR2 and GST-PDGFRβ are then added to the microtiter wells in 2 × concentration kinase dilution buffer consisting of 100 mM HEPES, 50 mM NaCl, 40 μM NaVO4, and 0.02% (w/v) BSA. The final enzyme concentration for GST-VEGFR2 or GST-PDGFRβ is 50 ng/mL. Twenty-five μL of diluted Sunitinib are subsequently added to each reaction well to produce a range of inhibitor concentrations appropriate for each enzyme. The kinase reaction is initiated by the addition of different concentrations of ATP in a solution of MnCl2 so that the final ATP concentrations spanned the Km for the enzyme, and the final concentration of MnCl2 is 10 mM. The plates are incubated for 5-15 minutes at room temperature before stopping the reaction with the addition of EDTA. The plates are then washed three times with TBST. Rabbit polyclonal antiphosphotyrosine antisera are added to the wells at a 1:10,000 dilution in TBST containing 0.5% (w/v) BSA, 0.025% (w/v) nonfat dry milk, and 100 μM NaVO4 and incubated for 1 hour at 37 °C. The plates are then washed three times with TBST, followed by the addition of goat antirabbit antisera conjugated with horseradish peroxidase (1:10,000 dilution in TBST). The plates are incubated for 1 hour at 37 °C and then washed three times with TBST. The amount of phosphotyrosine in each well is quantitated after the addition of 2,2′-azino-di-[3-ethylbenzthiazoline sulfonate] as substrate.[2]
[1]. J Med Chem. 2003;46(7):1116-9; Clin Cancer Res. 2003;9(1):327-37; Blood. 2003;101(9):3597-605. [2]. Sun L, et al. J Med Chem, 2003, 46(7), 1116-1119.