Novel curcumin- and emodin-related compounds identified by in silico 2D/3D conformer screening induce apoptosis in tumor cells

BackgroundInhibition of the COP9 signalosome (CSN) associated kinases CK2 and PKD by curcumin causes stabilization of the tumor suppressor p53. It has been shown that curcumin induces tumor cell death and apoptosis. Curcumin and emodin block the CSN-directed c-Jun signaling pathway, which results in diminished c-Jun steady state levels in HeLa cells. The aim of this work was to search for new CSN kinase inhibitors analogue to curcumin and emodin by means of an in silico screening method.MethodsHere we present a novel method to identify efficient inhibitors of CSN-associated kinases. Using curcumin and emodin as lead structures an in silico screening with our in-house database containing more than 106 structures was carried out. Thirty-five compounds were identified and further evaluated by the Lipinski's rule-of-five. Two groups of compounds can be clearly discriminated according to their structures: the curcumin-group and the emodin-group. The compounds were evaluated in in vitro kinase assays and in cell culture experiments.ResultsThe data revealed 3 compounds of the curcumin-group (e.g. piceatannol) and 4 of the emodin-group (e.g. anthrachinone) as potent inhibitors of CSN-associated kinases. Identified agents increased p53 levels and induced apoptosis in tumor cells as determined by annexin V-FITC binding, DNA fragmentation and caspase activity assays.ConclusionOur data demonstrate that the new in silico screening method is highly efficient for identifying potential anti-tumor drugs.

[1]  Dean P. Jones,et al.  EF24, a novel synthetic curcumin analog, induces apoptosis in cancer cells via a redox-dependent mechanism , 2005, Anti-cancer drugs.

[2]  Jürgen Bajorath,et al.  Virtual screening methods that complement HTS. , 2004, Combinatorial chemistry & high throughput screening.

[3]  D. Cantrell,et al.  Intracellular location and cell context-dependent function of protein kinase D. , 2003, Immunity.

[4]  S. Hilsenbeck,et al.  p53 mutation and tamoxifen resistance in breast cancer. , 1995, Clinical cancer research : an official journal of the American Association for Cancer Research.

[5]  Leila Mohammadi,et al.  BMC Cancer , 2001 .

[6]  E. Slee,et al.  To die or not to die: how does p53 decide? , 2004, Oncogene.

[7]  M. Athanassiou,et al.  Stabilization and reactivation of the p53 tumor suppressor protein in nontumorigenic revertants of HeLa cervical cancer cells. , 1999, Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research.

[8]  R. Offringa,et al.  Eradication of adenovirus E1-induced tumors by E1A-specific cytotoxic T lymphocytes , 1989, Cell.

[9]  R. Snyder,et al.  Assessment of the sensitivity of the computational programs DEREK, TOPKAT, and MCASE in the prediction of the genotoxicity of pharmaceutical molecules , 2004, Environmental and molecular mutagenesis.

[10]  J. Levine,et al.  Surfing the p53 network , 2000, Nature.

[11]  C Haanen,et al.  A novel assay for apoptosis. Flow cytometric detection of phosphatidylserine expression on early apoptotic cells using fluorescein labelled Annexin V. , 1995, Journal of immunological methods.

[12]  H. Yeger,et al.  Curcumin and resveratrol induce apoptosis and nuclear translocation and activation of p53 in human neuroblastoma. , 2004, Anticancer research.

[13]  F. Fitzpatrick,et al.  Curcumin impairs tumor suppressor p53 function in colon cancer cells. , 2004, Carcinogenesis.

[14]  R. Kraft,et al.  COP9 signalosome‐specific phosphorylation targets p53 to degradation by the ubiquitin system , 2001, The EMBO journal.

[15]  A. Levine,et al.  Surfing the p53 network , 2000, Nature.

[16]  Jeremy L Jenkins,et al.  Virtual screening to enrich hit lists from high‐throughput screening: A case study on small‐molecule inhibitors of angiogenin , 2002, Proteins.

[17]  B. Aggarwal,et al.  Nuclear factor‐κB and IκB kinase are constitutively active in human pancreatic cells, and their down‐regulation by curcumin (diferuloylmethane) is associated with the suppression of proliferation and the induction of apoptosis , 2004, Cancer.

[18]  F. Hoppe-Seyler,et al.  Repression of endogenous p53 transactivation function in HeLa cervical carcinoma cells by human papillomavirus type 16 E6, human mdm-2, and mutant p53 , 1993, Journal of virology.

[19]  M. Karin,et al.  AP-1 as a regulator of cell life and death , 2002, Nature Cell Biology.

[20]  S. K. Lee,et al.  Emodin, an anthraquinone derivative isolated from the rhizomes of Rheum palmatum, selectively inhibits the activity of casein kinase II as a competitive inhibitor. , 1999, Planta medica.

[21]  S. Pal,et al.  Curcumin induces apoptosis in human breast cancer cells through p53‐dependent Bax induction , 2002, FEBS letters.

[22]  Xin Chen,et al.  Performance of Similarity Measures in 2D Fragment-Based Similarity Searching: Comparison of Structural Descriptors and Similarity Coefficients , 2002, J. Chem. Inf. Comput. Sci..

[23]  K. Lam,et al.  New approaches in identifying drugs to inactivate oncogene products. , 2004, Seminars in cancer biology.

[24]  M. Seeger,et al.  The COP9 signalosome: at the interface between signal transduction and ubiquitin-dependent proteolysis. , 2002, Journal of cell science.

[25]  O. Medalia,et al.  Protein kinase CK2 and protein kinase D are associated with the COP9 signalosome , 2003, The EMBO journal.

[26]  Martin Thimm,et al.  Comparison of 2D Similarity and 3D Superposition. Application to Searching a Conformational Drug Database , 2004, J. Chem. Inf. Model..

[27]  L. Chiang,et al.  Emodin-induced apoptosis through p53-dependent pathway in human hepatoma cells. , 2004, Life sciences.

[28]  R. Kraft,et al.  A novel protein complex involved in signal transduction possessing similarities to 26S proteasome subunits , 1998, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[29]  K. Ferrell,et al.  COP9 Signalosome-directed c-Jun Activation/Stabilization Is Independent of JNK* , 1999, The Journal of Biological Chemistry.

[30]  Y. Lou,et al.  Inhibitory effects of dietary curcumin on forestomach, duodenal, and colon carcinogenesis in mice. , 1994, Cancer research.

[31]  S. Moro,et al.  Toward the rational design of protein kinase casein kinase-2 inhibitors. , 2002, Pharmacology & therapeutics.

[32]  S. Rees,et al.  Application of β-Galactosidase Enzyme Complementation Technology as a High Throughput Screening Format for Antagonists of the Epidermal Growth Factor Receptor , 2001 .

[33]  K. Ferrell,et al.  Comparison of human COP9 signalosome and 26S proteasome ‘lid’ , 1999, Molecular Biology Reports.

[34]  S. Hilsenbeck,et al.  Mutation and Tamoxifen Resistance in Breast Cancer ’ , 2005 .

[35]  P. M. Campbell,et al.  Honokiol, a Small Molecular Weight Natural Product, Inhibits Angiogenesis in Vitro and Tumor Growth in Vivo* , 2003, Journal of Biological Chemistry.

[36]  K. Youssef,et al.  Synthesis and Antitumor Activity of Some Curcumin Analogs , 2005, Archiv der Pharmazie.

[37]  J. Węsierska‐Gądek,et al.  Escape of p53 protein from E6‐mediated degradation in HeLa cells after cisplatin therapy , 2002, International journal of cancer.

[38]  C. Lipinski.  Drug-like properties and the causes of poor solubility and poor permeability. , 2000, Journal of pharmacological and toxicological methods.

[39]  M. Naumann,et al.  The constitutive photomorphogenesis 9 signalosome directs vascular endothelial growth factor production in tumor cells. , 2001, Cancer research.

[40]  J. Arbiser,et al.  Curcumin Is an In Vivo Inhibitor of Angiogenesis , 1998, Molecular medicine.

[41]  T. Seufferlein,et al.  Protein kinase D: a family affair , 2003, FEBS letters.