Identification of novel extracellular signal-regulated kinase docking domain inhibitors.
The extracellular signal regulated kinase (ERK1 and ERK2) signal transduction pathways play a critical role in cell proliferation. Hyperactivation of the ERK proteins either through increased expression of membrane-bound growth factor receptors or genetic mutations of upstream proteins is thought to be involved in the pathogenesis of many human cancers. Thus, targeted 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 the ATP binding region, which is well conserved among the protein kinase families. Taking advantage of recently identified ERK docking domains, which are reported to facilitate substrate protein interactions, we have used computer-aided drug design (CADD) to identify novel small molecular weight ERK inhibitors. Following a CADD screen of over 800 000 molecules, 80 potential compounds were selected and tested for activity in biological assays. Several compounds inhibited ERK-specific phosphorylation of ribosomal S6 kinase-1 (Rsk-1) or the ternary complex factor Elk-1 (TCF/Elk-1), both of which are involved in promoting cell proliferation. Active compounds showed a dose-dependent reduction in the proliferation of several cancer cell lines as measured by colony survival assays. Direct binding between the active compounds and ERK2 was indicated by fluorescence quenching. These active compounds may serve as lead candidates for development of novel specific inhibitors of ERK-substrate interactions involved in cell proliferation.
Department of Pharmaceutical Sciences, School of Pharmacy, and Molecular and Cell Biology Program, University of Maryland, Baltimore, 21201, USA.
Chad N
CN
Hancock
Alba
A
Macias
Eun Kyoung
EK
Lee
Su Yeon
SY
Yu
Alexander D
AD
Mackerell
Paul
P
Shapiro
D001665:Binding Sites; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003198:Computer Simulation; D004268:DNA-Binding Proteins / Q000378:metabolism; D016208:Databases, Factual; D015195:Drug Design; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D021281:Quantitative Structure-Activity Relationship; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D050807:ets-Domain Protein Elk-1
D004268:DNA-Binding Proteins; C494112:ELK1 protein, human; D047428:Protein Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; C069329:RPS6KA1 protein, human; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D019950:Mitogen-Activated Protein Kinase 1