The extracellular signal regulated kinase (ERK1 and ERK2) signalling pathway plays a critical role in cell proliferation. Activation of the ERK proteins either through increased expression of growth factor receptors or genetic mutations of upstream proteins is thought to be involved in the pathogenesis of many human cancers. Thus, inhibition of ERK signaling is viewed as a potential approach to prevent cancer cell proliferation. Currently, no specific inhibitors of the ERK proteins exist. Moreover, most kinase inhibitors lack specificity because they target ATP binding sites, which are well conserved among the protein kinase families. Taking advantage of recently identified ERK2 docking domains, which are reported to facilitate substrate interactions, we have used computer-aided drug design (CADD) to identify novel low molecular weight ERK inhibitors. We hypothesize that low molecular weight compounds that bind to the ERK2 docking domains will selectively block ERK interactions with substrate proteins and inhibit cell proliferation. Following CADD screening, potential compounds were selected and tested for activity in biological assays. Several compounds identified inhibited ERK-specific phosphorylation of ribosomal S6 kinase-1 (RSK-1) and the transcription factor, ELK-1, both of which promote cell proliferation. In addition, active compounds showed a dose-dependent reduction in the proliferation of cancer cell lines as measured by colony survival assays and bind directly to ERK2 as indicated by fluorescence spectroscopy.
Aim 1 of the current application will extend the use of CADD to identify additional compounds with a high probability of binding to nine different putative binding pockets on the ERK2 docking domains. MAP kinase substrate phosphorylation assays will be used to characterize the biological activity of the test compounds. The specific interactions between the active compounds and ERK2 will be tested by fluorescence spectroscopy and X-ray crystallography in Aim 2. Lead compounds that inhibit ERK-substrate phosphorylation and bind to specific docking domains will then be tested for their ability to inhibit cancer cell proliferation in cell and animal models. At the end of this application, it is expected that a collection of lead compounds will be identified that block specific ERK-substrate interactions. These compounds will be appropriate for research tools and the development into novel chemotherapeutic agents aimed at treating cancers associated with elevated ERK pathway activity. ? ? ?
|Shah, Nirav G; Tulapurkar, Mohan E; Ramarathnam, Aparna et al. (2017) Novel Noncatalytic Substrate-Selective p38?-Specific MAPK Inhibitors with Endothelial-Stabilizing and Anti-Inflammatory Activity. J Immunol 198:3296-3306|
|Samadani, Ramin; Zhang, Jun; Brophy, Amanda et al. (2015) Small-molecule inhibitors of ERK-mediated immediate early gene expression and proliferation of melanoma cells expressing mutated BRaf. Biochem J 467:425-38|
|Mansour, Marc R; Abraham, Brian J; Anders, Lars et al. (2014) Oncogene regulation. An oncogenic super-enhancer formed through somatic mutation of a noncoding intergenic element. Science 346:1373-7|
|Zuurbier, Linda; Gutierrez, Alejandro; Mullighan, Charles G et al. (2014) Immature MEF2C-dysregulated T-cell leukemia patients have an early T-cell precursor acute lymphoblastic leukemia gene signature and typically have non-rearranged T-cell receptors. Haematologica 99:94-102|
|Jung, Kwan-Young; Samadani, Ramin; Chauhan, Jay et al. (2013) Structural modifications of (Z)-3-(2-aminoethyl)-5-(4-ethoxybenzylidene)thiazolidine-2,4-dione that improve selectivity for inhibiting the proliferation of melanoma cells containing active ERK signaling. Org Biomol Chem 11:3706-32|
|Zhang, Jun; Shapiro, Paul; Pozharski, Edwin (2012) Structure of extracellular signal-regulated kinase 2 in complex with ATP and ADP. Acta Crystallogr Sect F Struct Biol Cryst Commun 68:1434-9|
|Raman, E Prabhu; Vanommeslaeghe, Kenno; Mackerell Jr, Alexander D (2012) Site-Specific Fragment Identification Guided by Single-Step Free Energy Perturbation Calculations. J Chem Theory Comput 8:3513-3525|
|Willis, Chris D; Oashi, Taiji; Busby, Ben et al. (2012) Hydrophobic residues in small ankyrin 1 participate in binding to obscurin. Mol Membr Biol 29:36-51|
|Foster, Theresa J; MacKerell Jr, Alexander D; Guvench, Olgun (2012) Balancing target flexibility and target denaturation in computational fragment-based inhibitor discovery. J Comput Chem 33:1880-91|
|Boston, Sarice R; Deshmukh, Rahul; Strome, Scott et al. (2011) Characterization of ERK docking domain inhibitors that induce apoptosis by targeting Rsk-1 and caspase-9. BMC Cancer 11:7|
Showing the most recent 10 out of 29 publications