MEK1 (IC50 = 17 nM); MEK2 (IC50 = 17 nM)

CI-1040 has an IC50 of 17 nM and directly inhibits MEK1. Additionally, a panel of related kinases with IC50 values more than 2.5 orders of magnitude higher has been shown to have little activity against it. The phosphorylation of ERK induced by mitogens is completely blocked when whole cells are treated with CI-1040. In MDA-MB-231 breast cancer cells, CI-1040 at a concentration of 1 μM is found to inhibit ERK1 and ERK2 phosphorylation by 99% and 92%, respectively[1]. In U-937 cells, CI-1040 causes apoptosis and blocks proliferation in a dose- and time-dependent manner. PUMA mRNA and protein levels significantly rise in response to CI-1040[2].

The systemic administration of the MEK inhibitor CI-1040 significantly improves lung structure while cutting adenoma formation by one-third. Without obviously having an impact on pneumocyte differentiation, CL-1040-treated mice have less lung cell proliferation[3].

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In vivo, the systemic administration of the MEK inhibitor CI-1040 reduced adenoma formation to a third and significantly restored lung structure. The proliferation rate of lung cells of mice treated with CL-1040 was decreased without any obvious effects on differentiation of pneumocytes. In contrast, the Raf inhibitor BAY 43-9006 did not influence adenoma formation in vivo. Conclusion: The MEK inhibitor CI-1040 may be used for the treatment of Ras and/or Raf-dependent human malignancies.[3]

Myelin basic protein (MBP) is phosphorylated by activated MAP kinase after it has been activated by MEK.When glutathione S-transferase (GST) fusion proteins made of the 44-kDa MAPK (GST-MAPK) or the 45-kDa MEK (GST-MEK1) are present, the incorporation of 32P into myelin basic protein (MBP) is measured. Assays are carried out in 50 mL of 50 mM Tris, pH 7.4, 10 mM MgCl2, 2 mM EGTA, and 10 μM [γ-32P]ATP containing 10 μg of GST-MEK1, 0.5 μg of GST-MAPK, and 40 μg of MBP. Reactions are stopped by adding Laemmli SDS sample buffer after 15 minutes of incubation at 30°C. SDS/10% PAGE resolves phosphorylated MBP. The result of this screening process is the identification of several small-molecule MEK inhibitors, including CI-1040. With a 50% inhibitory concentration (IC50) of 17 nM, experiments examining the order of addition reveal that CI-1040 directly inhibits MEK1 without affecting the activity of MAPK.

In cell culture, the MEK inhibitor CI-1040 is used at a final concentration of 50 mg/mL after being dissolved in DMSO as 10 mM stock solutions. After pretreatment with 5 and 20 uM CI-1040 for 24 hours, U-937 cells are transfected for 48 hours with either wt-p53 siRNA or PUMA siRNA. Then each well receives 20 mL of the MTT solution, and the process is repeated for a further 2 hours. In order to dissolve the MTT formazan produced by metabolically viable cells in 100 mL of isopropanol, the supernatant is aspirated after the experiment is finished. A plate reader is used to measure absorbance at 595 nm after the plates have been mixed for 30 minutes on a gyratory shaker[2].

Mice: By administering constitutively active C-Raf kinase to the lung, a lung cancer mouse model is produced. A daily intraperitoneal injection of BAY 43-9006 or CI-1040 is given starting at the age of 4 months for a total of 21 days at a dose of 100 mg/kg. At the conclusion of the treatment period, the lungs were separated and examined[3].

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In this study, researchers have generated a lung cancer mouse model by targeting constitutively active C-Raf kinase to the lung. These mice develop adenomas within 4 months of life. At this time-point they received daily intraperitoneal injections of either 100 mg/kg BAY 43-9006 or CI-1040 for additional 21 days. Thereafter, lungs were isolated and the following parameters were analyzed using histology and immunohistochemistry: overall lung structure, frequency of adenoma foci, proliferation rate, ERK activity, caspase-3 activation, and lung differentiation.[3]

[1]. CI-1040 (PD184352), a targeted signal transduction inhibitor of MEK (MAPKK). Semin Oncol. 2003 Oct;30(5 Suppl 16):105-16.

[2]. MEK inhibitor CI-1040 induces apoptosis in acute myeloid leukemia cells in vitro. Eur Rev Med Pharmacol Sci. 2016 May;20(10):1961-8.

[3]. Use of mitogenic cascade blockers for treatment of C-Raf induced lung adenoma in vivo: CI-1040strongly reduces growth and improves lung structure. BMC Cancer. 2004 Jun 1;4:24.

2-(2-chloro-4-iodoanilino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide is an aminobenzoic acid.
CI-1040 has been used in trials studying the treatment of Lung Cancer, Breast Cancer, Breast Neoplasms, Pancreatic Cancer, and Colorectal Cancer, among others.
MEK Inhibitor CI-1040 is an agent that inhibits both mitogen-activated protein kinase kinases 1 and 2 (MEK1 and MEK2), substrates of Raf and phosphorylates extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2), preventing phosphorylation and activation of the Mitogen-Activated Protein Kinase (MAPK) pathways, involved with signal transduction pathways and tumor proliferation.

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Several key growth factors, cytokines, and proto-oncogenes transduce their growth- and differentiation-promoting signals through the mitogen-activated protein kinase or extracellular signal-regulated protein kinase (ERK) cascade. Overexpression or constitutive activation of this pathway has been shown to play an important role in the pathogenesis and progression of breast and other cancers, making the components of this signaling cascade potentially important as therapeutic targets. CI-1040 (PD184352) is an orally active, highly specific, small-molecule inhibitor of one of the key components of this pathway (MEK1/MEK2), and thereby effectively blocks the phosphorylation of ERK and continued signal transduction through this pathway. Antitumor activity has been seen in preclinical models with this compound, particularly for pancreas, colon, and breast cancers, which has been shown to correlate with its inhibition of pERK. Clinically, CI-1040 has been shown to be well tolerated in phase I studies, with safety and pharmacokinetic profiles that permit continuous daily dosing. Biomarker studies have shown target inhibition in patients, and antitumor activity has also been observed with a partial response in one patient with pancreatic cancer and stable disease in approximately 25% of phase I patients. Given the central role of the ERK/mitogen-activated protein kinase pathway in mediating growth-promoting signals for a diverse group of upstream stimuli, inhibitors of MEK, as a key central mediator, could have significant clinical benefit in the treatment of breast and other cancers.[1]

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Objective: MEK1/2 (mitogen-activated protein kinase 1 and 2)/ERK1/2 (extracellular signal-regulated kinase 1 and 2) is important transducers of external signals for cell growth, survival, and apoptosis in acute myeloid leukemia cells (AML). In this study, we analyzed the effect of MEK inhibitor CI-1040 on the survival of AML cells. Materials and methods: Using ELISA and MTT we studied the cytotoxic effects of CI-1040 on AML U-937 cells. We studied the changes induced by CI-1040 on PUMA and p53 expression in U-937 cells by Western blotting assay. Moreover, we analyzed the cytotoxic effect of CI-1040 in U-937 cells with deleted PUMA, wt-p53 by wt-p53 siRNA and PUMA siRNA transfection. Results: CI-1040 induced apoptosis and inhibited proliferation in U-937 cells in a dose and time-dependent manner. CI-1040 induced a significant increase in PUMA mRNA and protein levels. Importantly, we show that knockdown of PUMA by PUMA siRNA transfection inhibited CI-1040-induced apoptosis and proliferation inhibition in U-937 cells. Moreover, CI-1040 induced apoptosis and proliferation inhibition was irrespective of wt-P53 status. Conclusions: These results demonstrate that CI-1040 induce apoptosis of U-937 cells and might be a new therapeutic option for the treatment of AML.[2]

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Background: Signaling networks promoting cell growth and proliferation are frequently deregulated in cancer. Tumors often are highly dependent on such signaling pathways and may become hypersensitive to downregulation of key components within these signaling cascades. The classical mitogenic cascade transmits stimuli from growth factor receptors via Ras, Raf, MEK and ERK to the cell nucleus and provides attractive molecular targets for cancer treatment. For example, Ras and Raf kinase inhibitors are already in a number of ongoing phase II and phase III clinical trials. In this study the effect of the Raf kinase inhibitor BAY 43-9006 and of the MEK inhibitor CI-1040 (PD184352) on a Raf dependent lung tumor mouse model was analyzed in detail. Methods: We have generated a lung cancer mouse model by targeting constitutively active C-Raf kinase to the lung. These mice develop adenomas within 4 months of life. At this time-point they received daily intraperitoneal injections of either 100 mg/kg BAY 43-9006 or CI-1040 for additional 21 days. Thereafter, lungs were isolated and the following parameters were analyzed using histology and immunohistochemistry: overall lung structure, frequency of adenoma foci, proliferation rate, ERK activity, caspase-3 activation, and lung differentiation. Results: Both inhibitors were equally effective in vitro using a sensitive Raf/MEK/ERK ELISA. In vivo, the systemic administration of the MEK inhibitor CI-1040 reduced adenoma formation to a third and significantly restored lung structure. The proliferation rate of lung cells of mice treated with CL-1040 was decreased without any obvious effects on differentiation of pneumocytes. In contrast, the Raf inhibitor BAY 43-9006 did not influence adenoma formation in vivo. Conclusion: The MEK inhibitor CI-1040 may be used for the treatment of Ras and/or Raf-dependent human malignancies.[3]

C17H14CLF2IN2O2

478.67

477.975

C, 42.66; H, 2.95; Cl, 7.41; F, 7.94; I, 26.51; N, 5.85; O, 6.69

212631-79-3

6918454

White to off-white solid powder

1.7±0.1 g/cm3

166-169ºC

1.656

8.01

2

5

6

25

472

0

IC1C([H])=C([H])C(=C(C=1[H])Cl)N([H])C1C(=C(C([H])=C([H])C=1C(N([H])OC([H])([H])C1([H])C([H])([H])C1([H])[H])=O)F)F

GFMMXOIFOQCCGU-UHFFFAOYSA-N

InChI=1S/C17H14ClF2IN2O2/c18-12-7-10(21)3-6-14(12)22-16-11(4-5-13(19)15(16)20)17(24)23-25-8-9-1-2-9/h3-7,9,22H,1-2,8H2,(H,23,24)

2-(2-chloro-4-iodoanilino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide

PD 184352; CI-1040; PD184352 (CI-1040); 2-(2-chloro-4-iodophenylamino)-N-cyclopropylmethoxy-3,4-difluorobenzamide; CI1040; PD-184352; 2-(2-chloro-4-iodophenylamino)-N-(cyclopropylmethoxy)-3,4-difluorobenzamide; PD184352 (CI-1040); 2-(2-chloro-4-iodophenylamino)-N-cyclopropylmethoxy-3,4-difluorobenzamide; PD184352; CI 1040

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: ≥ 2.5 mg/mL (5.22 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 25.0 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: ≥ 2.08 mg/mL (4.35 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 3: 30% PEG400+0.5% Tween80+5% propylene glycol, pH 9: 10mg/mL

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