Background:

AZD6244 is a highly potent and selective inhibitor of MEK1/2 with IC50 value of 14.1nM against MEK1 [1].

AZD6244 is a second generation MEK1/2 inhibitor. In the radioactive assay, AZD6244 shows potent inhibition against the purified MEK1without the competition with ATP. Besides, it is a selective inhibitor since it has no obvious inhibition against other tyrosine kinases including MKK6, EGFR, ErbB2 and B-Raf et al. In the cellular assay, AZD6244 inhibits the phosphorylation of ERK1/2 which are the direct substrates of MEK1/2. The IC50 value is 10.3nM. It also inhibits the EGF-induced phosphorylation of ERK1/2 but not ERK5 in A431 cells. Since MEK is important in cell proliferation, the block of MEK1/2 caused by AZD6244 leads to a growth inhibition in the cell lines containing activating B-Raf and Ras mutations with IC50 values ranging from 59 to 473nM. Furthermore, the administration of AZD6244 can significantly inhibit tumor growth both in the HT-29 xenograft model and the BxPC3 pancreatic tumor xenograft model [1].

参考文献:
[1] Yeh TC, Marsh V, Bernat BA, Ballard J, Colwell H, Evans RJ, Parry J, Smith D, Brandhuber BJ, Gross S, Marlow A, Hurley B, Lyssikatos J, Lee PA, Winkler JD, Koch K, Wallace E. Biological characterization of ARRY-142886 (AZD6244), a potent, highly selective mitogen-activated protein kinase kinase 1/2 inhibitor. Clin Cancer Res. 2007 Mar 1;13(5):1576-83.