APS-2-79

APS-2-79 behaves as a kinase suppressor of Ras (KSR)-dependent antagonist of RAF-mediated MEK phosphorylation. APS-2-79 binds directly to KSR2 within the KSR2-MEK1 complex with an IC 50 of 120±23 nM for KSR2.

Signaling Pathways >> MAPK/ERK Pathway >> MEK

Research Areas >> Cancer

KSR2:120 nM (IC50)

MEK1

APS-2-79 (1 μM) shifts the cell viability dose response to Trametinib in Ras-mutant cell lines HCT-116 and A549, but not BRAF mutant cell lines SK-MEL-239 and A375. Although the cellular effects of APS-2-79 alone are modest, combination analysis over full concentration matrices reveal that kinase suppressor of Ras (KSR)-inactive state (KSRi) synergizes with Trametinib, and other MEK inhibitors, specifically in KRAS mutant cell lines. APS-3-77, and additional control compounds, do not demonstrate Ras-mutant-specific synergy, supporting the hypothesis that the enhanced activity of Trametinib when combined with APS-2-79 depends on co-modulation of KSR[1].

Cell viability assays are performed in 96 well plates. Optimal cell densities for 96 well plate assays are determined to obtain linear growth over the time course of assays. A549, HCT-116, A375, SK-MEL-239, COLO-205, LOVO, SK-MEL-2, CALU-6, MEWO, SW620 and SW1417 cells are plated at 500 cells per well and treated with inhibitors (e.g., APS-2-79; 100-3,000 nM) for 72hrs before measuring viability. H2087 and HEPG2 cells are plated at 2000 cells per well, and treated with inhibitors (e.g., APS-2-79; 100-3,000 nM) for 72hrs. Cell viability is measured using Resazurin, and the percent cell viability is determined by normalizing inhibitor-treated samples to DMSO controls[1].

[1]. Dhawan NS, et al. Small molecule stabilization of the KSR inactive state antagonizes oncogenic Ras signalling. Nature. 2016 Aug 24;537(7618):112-116.

U0126-EtOH | PD98059 | Trametinib (GSK1120212) | PD0325901 | Selumetinib (AZD6244) | Cobimetinib | MEK162(ARRY-162,ARRY-438162) | PD184352 (CI-1040) | RO 5126766 | Isorhamnetin | AS703026 | RGB-286638 | BIX02188 | BIX02189 | SL-327