Targeting Ovarian Tumor Cell Adhesion Mediated by Tissue Transglutaminase
| Autor: | May Khanna, Aruna Gavini, David Courtney, Minghai Shao, Liwei Li, Samy O. Meroueh, Daniela Matei, Bhadrani Chelladurai, John J. Turchi |
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| Rok vydání: | 2011 |
| Předmět: |
Models
Molecular Cancer Research Tissue transglutaminase Molecular Sequence Data Allosteric regulation Fluorescence Polarization Protein Structure Secondary GTP-Binding Proteins Cell Line Tumor Cell Adhesion Humans Immunoprecipitation Protein Glutamine gamma Glutamyltransferase 2 Amino Acid Sequence Enzyme Inhibitors Cell adhesion Ovarian Neoplasms Binding Sites Transglutaminases Molecular Structure biology Cell adhesion molecule Chemistry Adhesion Surface Plasmon Resonance Small molecule Molecular biology Peptide Fragments Fibronectins Protein Structure Tertiary Fibronectin Oncology Cancer cell biology.protein Biophysics Thiazolidines Benzimidazoles Female Crystallization Protein Binding |
| Zdroj: | Molecular Cancer Therapeutics. 10:626-636 |
| ISSN: | 1538-8514 1535-7163 |
| DOI: | 10.1158/1535-7163.mct-10-0912 |
| Popis: | Tissue transglutaminase (TG2) is a transpeptidase involved in protein cross-linking through generation of ϵ-(γ-glutamyl)lysine isopeptide bonds. It also promotes cell adhesion through interaction with fibronectin and facilitates formation of fibronectin–integrin complexes. This interaction is involved in tumor cell adhesion to the matrix and in the process of tumor dissemination. Its inhibition by small molecules may therefore be useful in blocking metastasis. To that end, we screened more than 800,000 compounds following an in silico docking approach targeting two distinct cavities in the vicinity of the fibronectin-binding site on TG2. A total of 120 compounds were acquired and tested in cell culture–based assays for inhibition of ovarian tumor cell adhesion and proliferation. Seven compounds showed more than 50% inhibition of cell adhesion at a concentration of 25 μmol/L. A follow-up fluorescence polarization study revealed that one compound in particular (ITP-79) inhibited binding of a TG2 peptide to a 42-kDa fragment of fibronectin in a dose-dependent manner. This inhibition was confirmed in cancer cells by coimmunoprecipitation. A competition assay with surface plasmon resonance showed that ITP-79 modulated binding of TG2 to fibronectin. Direct binding of compounds that inhibited adhesion to TG2 were examined with differential scanning fluorimetry, which measures the effect of the compound on the melting temperature of the target. Two compounds, including ITP-79, reduced TG2 stabilization, mimicking the effects of GTP, a known negative allosteric regulator of TG2 enzymatic function. This suggests a potential allosteric mechanism for the compound in light of its distal target site. Mol Cancer Ther; 10(4); 626–36. ©2011 AACR. |
| Databáze: | OpenAIRE |
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