c-Kit (IC50 ~100 nM); Bcr-Abl (IC50 ~100 nM); PDGFR (IC50 ~100 nM)

Imatinib (STI571) Mesylate prevents c-Kit autophosphorylation, MAPK activation, and Akt activation without changing the overall amounts of c-kit, MAPK, or Akt protein. About 100 nM is the concentration that results in 50% inhibition for these effects[1]. The kinase Bcr-Abl that causes chronic myeloid leukemia is highly susceptible to imatinib (STI571) mesylate (in vitro IC50 of 25 nM). Moreover, imatinib effectively inhibits PDGFR (in vitro IC50, 380 nM) and Kit (in vitro IC50, 410 nM)[2]. Imatinib (STI571) mesylate is a multi-target inhibitor of v-Abl, c-Kit, and it also inhibits the native PDGFβ receptor, Bcr/Abl, v-Abl, Tel/Abl, and c-Kit. However, it does not inhibit the EGFR, c-Fms, Flt3, Src family kinases, or numerous other tyrosine kinases. Imatinib has no effect on untransformed Ba/F3 cells growing in IL-3 or on Ba/F3 cells transformed by Tel/JAK2[3]. However, it inhibits the tyrosine phosphorylation and cell growth of Ba/F3 cells expressing Bcr/Abl, Tel/Abl, Tel/PDGFβR, and Tel/Arg with an IC50 of approximately 0.5 μM in each case. Imatinib mesylate specifically impedes c-Kit, PDGFR kinase, and Bcr/Abl activity. In patients with Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) and chronic myelogenous leukemia (CML), imatinib mesylate exhibits unique and swift antileukemic activity[4].

Imatinib has varying antitumor effects on three xenografted tumors made from surgical samples of newly diagnosed human small cell lung cancers: the growth of the SCLC6, SCLC61, and SCLC108 tumors is inhibited by 80%, 40%, and 78%, respectively, while the growth of SCLC74 is not significantly affected. When administered by gavage at 10, 20, and 40 mg/kg, respectively, Imatinib significantly reduces the high fat-induced lipid staining area in ApoE(-/-) mice fed a high fat diet by 30%, 27%, and 35% compared to high fat diet untreated controls and suppresses carotid artery lipid accumulation.

Rabbit antiserum is used to immunoprecipitate the PDGF receptor from extracts of BALB/c 3T3 cells, which is then left on ice for two hours. Antigen-antibody complexes are gathered using protein A-Sepharose beads. TNET (50 mM Tris, pH 7.5, 140 mM NaCl, 5 mM EDTA, 1% Triton X-100), TNE (50 mM Tris, pH 7.5, 140 mM EDTA), and kinase buffer (20 mM Tris, pH 7.5, 10 mM MgCl2) are the three solutions used to wash the immunoprecipitates twice. A variety of drug concentrations are added to the reaction mixture after PDGF (50 ng/mL) stimulation for 10 minutes at 4°C.

Twenty-four hours before the test compounds are added, tested A549 cells are arranged at a density of 5×10³ cells per well in 96-well flat-bottom plates. In addition to different doses of Imatinib mesylate (10, 100, 1000, and 10,000 ng/mL) and other cytostatic medications (Docetaxel (DTX) or Idarubicin (ID): 0.1, 1, 10, 100 ng/mL; Cisplatin (CIS): 1, 10, 100, 1000 ng/mL), the cells are incubated with PRI-2191 at two different concentrations (10 and 100 nM) for 96 hours. The assay known as sulforhodamine B (SRB) is utilized to assess the cytotoxic effect. As a result, the Dmitry Nevozhay software Cheburator 0.4 calculates the IC50 for every individual experiment[4].

Mice: We use female NOD/SCID mice that are 12–16 weeks old and weigh 20–25 g. On Day 0, mice receive a subcutaneous (s.c.) inoculation of A549 tumor cells suspension (5×10⁶ cells in 0.2 mL of Hank's medium per mouse). Following this, they are randomly assigned to groups that receive different combinations of vitamin D analogs and chemotherapeutics. In the corresponding experiments, one of the two experimental protocols is used: 1. After the tumor cells are injected, treatment begins on Day 7 (when the tumors become palpable). For 19 days (from Days 7 to 25), imatinib mesylate is given intraperitoneally (i.p.) at a dose of 75 mg/kg/day. PRI-2191 is given orally or s.c. three times a week (on Days 7, 12, 14, 16, 19, 21, and 23) at a dose of 2 μg/kg/day. 2. After tumor cells are injected, treatment begins on Day 7 (when tumors become palpable). For 13 days (from Days 7-19), imatinib mesylate is given intraperitoneally (i.p.) at a dose of 50 mg/kg/day. PRI-2191 and PRI-2205 are given subcutaneously (s.c.) three times a week (on Days 7, 10, 12, 14, 17, 19, 21, 24, and 26) at doses of 1 or 10 μg/kg/day, respectively. Blood is drawn while the mice are sedated at the conclusion of the trials, and they are then killed.
Rats: In the experiments, male Lewis rats weighing between 270 and 320 g are employed. The Imatinib group (n = 7) receives an intraperitoneal injection of Imatinib mesylate (50 mg/kg), while the vehicle group (n = 7) receives 0.5 mL of 20% DMSO without Imatinib. Preliminary testing reveals that the 25 mg/kg dose slightly improves lung function without reaching statistical significance. Based on previous reports and this result, the intraperitoneal administration of 50 mg/kg was chosen. The animals have a left thoracotomy, and a tiny metallic clamp is used to occlude the left hilum. The occlusion is carried out 20 minutes following the administration of imatinib or the vehicle. Tidal volume (TV) and respiratory rate (RR) are set to 8 mL/kg and 80 breaths/min, respectively, during clamping. The clamp is taken off after 90 minutes of ischemia, and reperfusion is sustained for an additional 120 minutes. The bilateral lung's blood flow and ventilation are restored during reperfusion. The animals in the sham group (n=6) undergo 210 minutes of ventilation, thoracotomy, and heparinization.

[1]. Inhibition of c-kit receptor tyrosine kinase activity by STI 571, a selective tyrosine kinase inhibitor. Blood. 2000 Aug 1;96(3):925-32.

[2]. Sorafenib inhibits imatinib-resistant KIT and platelet-derived growth factor receptor beta gatekeeper mutants. Clin Cancer Res. 2007 Jun 1;13(11):3363-9.

[3]. ARG tyrosine kinase activity is inhibited by STI571.Blood. 2001 Apr 15;97(8):2440-8.

[4]. Vitamin D Analogs Potentiate the Antitumor Effect of Imatinib Mesylate in a Human A549 Lung Tumor Model. Int J Mol Sci. 2015 Nov 13;16(11):27191-207.

[5]. Protective Effects of Imatinib on Ischemia/Reperfusion Injury in Rat Lung. Ann Thorac Surg. 2016 Jul 23. pii: S0003-4975(16)30523-9.

[6]. Targeting invadopodia-mediated breast cancer metastasis by using ABL kinase inhibitors. Oncotarget. 2018 Apr 24;9(31):22158-22183.

C30H35N7O4S

589.71

589.2471238

C, 61.10; H, 5.98; N, 16.63; O, 10.85; S, 5.44

220127-57-1

Imatinib;152459-95-5;N-Desmethyl imatinib;404844-02-6

white to off-white to brownish or yellowish tinged crystalline powder

CC1=C(C=C(C=C1)NC(=O)C2=CC=C(C=C2)CN3CCN(CC3)C)NC4=NC=CC(=N4)C5=CN=CC=C5.CS(=O)(=O)O

YLMAHDNUQAMNNX-UHFFFAOYSA-N

InChI=1S/C29H31N7O.CH4O3S/c1-21-5-10-25(18-27(21)34-29-31-13-11-26(33-29)24-4-3-12-30-19-24)32-28(37)23-8-6-22(7-9-23)20-36-16-14-35(2)15-17-36;1-5(2,3)4/h3-13,18-19H,14-17,20H2,1-2H3,(H,32,37)(H,31,33,34);1H3,(H,2,3,4)

methanesulfonic acid;4-[(4-methylpiperazin-1-yl)methyl]-N-[4-methyl-3-[(4-pyridin-3-ylpyrimidin-2-yl)amino]phenyl]benzamide

STI571; CGP-57148B; ST-1571 Mesylate; CGP 57148; CGP57148; CGP-57148; CGP-57148B; CGP57148B; ; STI-571; STI 571; Imatinib mesylate; Brand name: Gleevec (USA); Glivec (other countries)

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)