CI-1040 (PD184352) is an orally active, highly specific, small-molecule inhibitor of MEK with an IC50 of 17 nM for MEK1.
CI-1040 directly inhibits MEK1 with an IC50 of 17 nM. It has also been shown to have little activity against a panel of related kinases with IC50 values more than 2.5 orders of magnitude higher. Treatment of whole cells with CI-1040 completely inhibits the mitogen-stimulated phosphorylation of ERK. CI-1040 at a concentration of 1 μM is found to inhibit phosphorylation of ERK1 and ERK2 by 99% and 92%, respectively in MDA-MB-231 breast cancer cells[1]. CI-1040 induces apoptosis and inhibits proliferation in U-937 cells in a dose and time-dependent manner. CI-1040 induces a significant increase in PUMA mRNA and protein levels[2].
The systemic administration of the MEK inhibitor CI-1040 reduces adenoma formation to a third and significantly restores lung structure. The proliferation rate of lung cells of mice treated with CL-1040 is decreased without any obvious effects on differentiation of pneumocytes[3].
References:
[1]. Allen LF, et al. CI-1040 (PD184352), a targeted signal transduction inhibitor of MEK (MAPKK). Semin Oncol. 2003 Oct;30(5 Suppl 16):105-16.
[2]. Wei CR, et al. 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]. Kramer BW, et al. 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.