ABSTRACT
A series of 2-pyrimidyl-5-amidothiophenes has been synthesized and evaluated for AKT inhibition. SAR studies resulted in potent inhibitors of AKT with IC(50) values as low as single digit nanomolar as represented by compound 2aa. Compound 2aa showed cellular activity including antiproliferation and downstream target modulation. Selectivity profile is described. A co-crystal of 2aa with PKA is determined and discussed.
Subject(s)
Chemistry, Pharmaceutical/methods , Enzyme Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Thiophenes/chemistry , Thiophenes/chemical synthesis , Cell Line, Tumor , Cell Proliferation , Crystallization , Crystallography, X-Ray , Humans , Inhibitory Concentration 50 , Models, Chemical , Models, Molecular , Protein Binding , Structure-Activity RelationshipABSTRACT
Overexpression studies have suggested that Siah1 proteins may act as effectors of p53-mediated cellular responses and as regulators of mitotic progression. We have tested these hypotheses using Siah gene knockout mice. Siah1a and Siah1b were not induced by activation of endogenous p53 in tissues, primary murine embryonic fibroblasts (MEFs) or thymocytes. Furthermore, primary MEFs lacking Siah1a, Siah1b, Siah2, or both Siah2 and Siah1a displayed normal cell cycle progression, proliferation, p53-mediated senescence, and G(1) phase cell cycle arrest. Primary thymocytes deficient for Siah1a, Siah2, or both Siah2 and Siah1a, E1A-transformed MEFs lacking Siah1a, Siah1b, or Siah2, and Siah1b-null ES cells all underwent normal p53-mediated apoptosis. Finally, inhibition of Siah1b expression in Siah2 Siah1a double-mutant cells failed to inhibit cell division, p53-mediated induction of p21 expression, or cell cycle arrest. Our loss-of-function experiments do not support a general role for Siah genes in p53-mediated responses or mitosis.
