PDGFRβ (IC50 = 2 nM); VEGFR2 (IC50 = 80 nM); FLT3; c-Kit

Sunitinib inhibits FLT-3 and Kit with considerable potency.[1] With a Ki of 9 nM and 8 nM, respectively, sunitinib is a strong ATP-competitive inhibitor of VEGFR2 (Flk1) and PDGFRβ. It provides >10-fold greater selectivity for VEGFR2 and PDGFR than FGFR-1, EGFR, Cdk2, Met, IGFR-1, Abl, and src. With IC50 values of 10 nM and 10 nM, respectively, sunitinib inhibits the phosphorylation of VEGFR2 in response to VEGF and PDGFRβ in response to PDGF in serum-starved NIH-3T3 cells expressing VEGFR2 or PDGFRβ. Sunitinib has an IC50 of 40 nM for VEGF-induced proliferation of serum-starved HUVECs and an IC50 of 39 nM and 69 nM for PDGF-induced proliferation of NIH-3T3 cells overexpressing PDGFRβ or PDGFRβ, respectively.[2] With an IC50 of 250 nM, 50 nM, and 30 nM, respectively, sunitinib inhibits the phosphorylation of wild-type FLT3, FLT3-ITD, and FLT3-Asp835. With IC50 values of 8 nM and 14 nM, respectively, sunitinib suppresses the growth of MV4;11 and OC1-AML5 cells and, in a dose-dependent fashion, triggers apoptosis.[3]

Sunitinib (20–80 mg/kg/day) exhibits broad and potent dose-dependent anti-tumor activity against a variety of tumor xenograft models, including HT-29, A431, Colo205, H-460, SF763T, C6, A375, or MDA-MB-435. This is consistent with the significant and selective inhibition of VEGFR2 or PDGFR phosphorylation and signaling in vivo. Six out of eight mice receiving 80 mg/kg/day of sunitinib for 21 days experience complete tumor regression, and 110 days after the end of the treatment, there is no regrowth of the tumor.Tumors that do not completely regress after the first round of treatment can still be successfully treated with sunitinib in a second round. Tumor MVD significantly decreases with sunitinib treatment, with SF763T glioma tumors reduced by approximately 40%. Tumor size remains unchanged, but luciferase-expressing PC-3M xenografts treated with SU11248 completely inhibits further tumor growth.[2] Treatment with sunitinib (20 mg/kg/day) increases survival in the FLT3-ITD bone marrow engraftment model and significantly suppresses the growth subcutaneous MV4;11 (FLT3-ITD) xenografts.[3]

Sunitinib's IC50 values against PDGFRβ and VEGFR2 (Flk-1) are ascertained by employing glutathione S-transferasefusion proteins that encompass the entire RTK cytoplasmic domain. In order to measure the trans-phosphorylation activity of VEGFR2 (Flk-1) and PDGFRβ, biochemical tyrosine kinase assays are carried out in 96-well microtiter plates that have been precoated (20 μg/well in PBS) and incubated with the peptide substrate poly-Glu,Tyr (4:1) for an entire night at 4 °C. Adding 1-5% (w/v) BSA to PBS blocks excess protein binding sites. The cells of insects infected with baculovirus produce purified GST-fusion proteins. The microtiter wells are then filled with GST-VEGFR2 and GST-PDGFRβ in a 2 × concentration kinase dilution buffer that contains 40 μM NaVO₄, 50 mM NaCl, 100 mM HEPES, and 0.02% (w/v) BSA. 50 ng/mL is the final enzyme concentration for GST-VEGFR2 or GST-PDGFRβ. To create a range of inhibitor concentrations suitable for every enzyme, 25 μL of diluted Sunitinib is then added to each reaction well. A solution of MnCl₂ is mixed with varying concentrations of ATP to start the kinase reaction. The final concentration of MnCl₂ is 10 mM, and the final ATP concentrations span the Km for the enzyme. After allowing the plates to sit at room temperature for five to fifteen minutes, the reaction is halted by adding EDTA. After that, TBST is used to wash the plates three times. After adding rabbit polyclonal antiphosphotyrosine antisera at a 1:10,000 dilution to the wells in TBST containing 0.025% (w/v) nonfat dry milk, 0.5% (w/v) BSA, and 100 μM NaVO₄, the wells are incubated at 37 °C for one hour. After three TBST washes, the plates are inoculated with goat anti-rabbit antisera conjugated with horseradish peroxidase (1:10,000 dilution in TBST). The plates are cleaned three times with TBST after an hour of incubation at 37 °C. Once 2,2′-azino-di-[3-ethylbenzthiazoline sulfonate] has been added as substrate, the amount of phosphotyrosine in each well is quantified.

The cells are starved for an entire night in a medium containing 0.1% FBS before FL (50 ng/mL; FLT3-WT cells only) and sunitinib are added. After 48 hours of culture, proliferation is assessed using trypan blue cell viability assays or the Alamar Blue assay. Apoptosis is quantified using Western blotting 24 hours after Sunitinib addition in order to identify caspase-3 levels or poly (ADP-ribose) polymerase (PARP) cleavage.

Mice: The mice used are female nu/nu (8–12 weeks old, 25 grams). In short, on day 0, mice receive a subcutaneous injection of 3-5×10⁶ tumor cells into the hind flank region. After tumors reach the indicated average size, mice bearing tumors are treated daily orally with carboxymethyl cellulose suspension or as a citrate buffered (pH 3.5) solution containing sunitinib. Tumor growth is assessed using tumor volume measurements taken twice a week. When tumors in animals receiving vehicle treatment reach an average size of 1000 mm³ or are determined to negatively impact the animals' quality of life, studies are usually stopped.
Rats: The Wistar rats are adult males weighing between 325 and 349 g. In two drug studies, the efficacy of the time-lapse imaging method in assessing the anti-angiogenic effects of a particular drug treatment is verified. First, mesenteric windows are taken from adult male Wistar rats, and the tissues are cultured for three days in two different experimental groups: 1) 10% serum (n = 8 tissues from 4 rats), and 2) 10% serum + Sunitinib (5 μM; n=8 tissues from 4 rats).

[1]. J Med Chem . 2003 Mar 27;46(7):1116-9.

[2]. Clin Cancer Res . 2003 Jan;9(1):327-37.

[3]. Blood . 2003 May 1;101(9):3597-605.

[4]. Mol Cancer Ther . 2003 Oct;2(10):1011-21.

[5]. Blood . 2004 Dec 15;104(13):4202-9.

[6]. Mol Cancer Ther . 2006 Oct;5(10):2522-30.

[7]. EMBO J . 2011 Mar 2;30(5):894-905.

C22H27FN4O2

398.47

398.21

C, 66.31; H, 6.83; F, 4.77; N, 14.06; O, 8.03

557795-19-4

Sunitinib Malate;341031-54-7;Sunitinib-d10;1126721-82-1;Sunitinib-d4;1126721-79-6

Yellow solid powder

CCN(CC)CCNC(=O)C1=C(NC(=C1C)/C=C\2/C3=C(C=CC(=C3)F)NC2=O)C

WINHZLLDWRZWRT-ATVHPVEESA-N

InChI=1S/C22H27FN4O2/c1-5-27(6-2)10-9-24-22(29)20-13(3)19(25-14(20)4)12-17-16-11-15(23)7-8-18(16)26-21(17)28/h7-8,11-12,25H,5-6,9-10H2,1-4H3,(H,24,29)(H,26,28)/b17-12-

N-[2-(diethylamino)ethyl]-5-[(Z)-(5-fluoro-2-oxo-1H-indol-3-ylidene)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide

SU11248; SU 11248; SU011248; SU-11248; sunitinib; trade name: Sutent.

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 1.11 mg/mL (2.79 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 11.1 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 1.11 mg/mL (2.79 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 11.1 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 3: 5% DMSO+corn oil: 7mg/mL

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 (Please use freshly prepared in vivo formulations for optimal results.)