Description: |
Selumetinib (AZD6244, ARRY-142886) is a potent, highly selective MEK inhibitor with IC50 of 14 nM for MEK1 and Kd value of 530 nM for MEK2. It also inhibits ERK1/2 phosphorylation with IC50 of 10 nM, no inhibition to p38α, MKK6, EGFR, ErbB2, ERK2, B-Raf, etc. Selumetinib suppresses cell proliferation, migration and trigger apoptosis. |
Targets: |
MEK1/MEK2 | ERK1/2 |
In vitro: |
Mol Cancer Ther,2010 Jul;9(7):1985-94. | Identification of common predictive markers of in vitro response to the Mek inhibitor selumetinib (AZD6244; ARRY-142886) in human breast cancer and non-small cell lung cancer cell lines.[Pubmed: 20587667] | Selumetinib (AZD6244; ARRY-142886) is a tight-binding, uncompetitive inhibitor of mitogen-activated protein kinase kinases (MEK) 1 and 2 currently in clinical development. METHODS AND RESULTS: We evaluated the effects of selumetinib in 31 human breast cancer cell lines and 43 human non-small cell lung cancer (NSCLC) cell lines to identify characteristics correlating with in vitro sensitivity to MEK inhibition. IC(50) <1 micromol/L (considered sensitive) was seen in 5 of 31 breast cancer cell lines and 15 of 43 NSCLC cell lines, with a correlation between sensitivity and raf mutations in breast cancer cell lines (P = 0.022) and ras mutations in NSCLC cell lines (P = 0.045). Evaluation of 27 of the NSCLC cell lines with Western blots showed no clear association between MEK and phosphoinositide 3-kinase pathway activation and sensitivity to MEK inhibition. Baseline gene expression profiles were generated for each cell line using Agilent gene expression arrays to identify additional predictive markers. Genes associated with differential sensitivity to selumetinib were seen in both histologies, including a small number of genes in which differential expression was common to both histologies.
CONCLUSIONS:
In total, these results suggest that clinical trials of selumetinib in breast cancer and NSCLC might select patients whose tumors harbor raf and ras mutations, respectively. |
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In vivo: |
Clin Cancer Res,2007 Mar 1;13(5):1576-83. | Biological characterization of ARRY-142886 (AZD6244), a potent, highly selective mitogen-activated protein kinase kinase 1/2 inhibitor.[Pubmed: 17332304] | The Ras-Raf-mitogen-activated protein kinase kinase (MEK) pathway is overactive in many human cancers and is thus a target for novel therapeutics. We have developed a highly potent and selective inhibitor of MEK1/2. The purpose of these studies has been to show the biological efficacy of ARRY-142886 (AZD6244) in enzymatic, cellular, and animal models.
METHODS AND RESULTS: The ability of ARRY-142886 to inhibit purified MEK1 as well as other kinases was evaluated. Its effects on extracellular signal-regulated kinase (ERK) phosphorylation and proliferation in several cell lines were also determined. Finally, the inhibitor was tested in HT-29 (colorectal) and BxPC3 (pancreatic) xenograft tumor models.The IC(50) of ARRY-142886 was determined to be 14 nmol/L against purified MEK1. This activity is not competitive with ATP, which is consistent with the high specificity of compound for MEK1/2. Basal and epidermal growth factor-induced ERK1/2 phosphorylation was inhibited in several cell lines as well as 12-O-tetradecanoylphorbol-13-acetate-induced ERK1/2 phosphorylation in isolated peripheral blood mononuclear cells. Treatment with ARRY-142886 resulted in the growth inhibition of several cell lines containing B-Raf and Ras mutations but had no effect on a normal fibroblast cell line. When dosed orally, ARRY-142886 was capable of inhibiting both ERK1/2 phosphorylation and growth of HT-29 xenograft tumors in nude mice. Tumor regressions were also seen in a BxPC3 xenograft model. In addition, tumors remained responsive to growth inhibition after a 7-day dosing holiday.
CONCLUSIONS: ARRY-142886 is a potent and selective MEK1/2 inhibitor that is highly active in both in vitro and in vivo tumor models. This compound is currently being investigated in clinical studies. |
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