title: The new InsP3Kinase inhibitor BIP-4 is competitive to InsP3 and blocks proliferation and adhesion of lung cancer cells.
abstract: As ectopic expression of the neuronal inositol-1,4,5-trisphosphate-3-kinase A (InsP3Kinase) in tumor cells increases the metastatic potential, InsP3Kinase is an interesting target for tumor therapy. Recently, we have identified a membrane-permeable InsP3Kinase inhibitor (BAMB-4) exhibiting an IC50-value of 20 μM. Here we characterized a new InsP3Kinase inhibitor which shows a 130-fold lower IC50 value (157 ± 57 nM) as compared to BAMB-4. We demonstrate that this nitrophenolic compound, BIP-4, is non-competitive to ATP but competitive to InsP3, thus exhibits a high selectivity for inhibition of InsP3Kinase activity. Docking analysis suggested a putative binding mode of this molecule into the InsP3Kinase active site. Determination of cellular uptake in lung cancer cells (H1299) revealed that 6% of extracellular BIP-4 is internalized by non-endosomal uptake, showing that BIP-4 is not trapped inside endo/lysosomes but is available to inhibit cellular InsP3Kinase activity. Interestingly, we found that BIP-4 mediated inhibition of InsP3Kinase activity in the two lung cancer cell lines H1299 and LN4323 inhibited proliferation and adhesion at IC50 values of 3 μM or 2 μM, respectively. InsP3Kinase inhibition did not alter ATP-induced calcium signals but significantly reduced the level of Ins(1,3,4,5,6)P5. From these data we conclude that the inhibitory effect of BIP-4 on proliferation and adhesion of lung cancer cells does not result from alterations of calcium but from alterations of inositol phosphate signals. In summary, we reveal that inhibition of cellular InsP3Kinase by BIP-4 impairs proliferation and adhesion and therefore BIP-4 might be a promising compound to reduce the metastatic potential of lung carcinoma cells.
authors.affiliation: UKE Hamburg, Institut für Biochemie und Signaltransduktion, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Schröder
authors.affiliation: UKE Hamburg, Institut für Biochemie und Molekular Zellbiologie, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Tödter
authors.affiliation: Department of Crystallography and Structural Biology, Institute of Physical Chemistry Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Gonzalez
authors.affiliation: Department of Crystallography and Structural Biology, Institute of Physical Chemistry Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain.
authors.forename: Elsa
authors.initials: E
authors.lastname: Franco-Echevarría
authors.affiliation: Heinrich-Pette-Institute Leibniz-Institute for Experimental Virology, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Gabor
authors.initials: G
authors.lastname: Rohaly
authors.affiliation: UKE Hamburg, Institut für Biochemie und Signaltransduktion, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Blecher
authors.affiliation: UKE Hamburg, Institut für Biochemie und Signaltransduktion, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Lin
authors.affiliation: UKE Hamburg, Institut für Biochemie und Signaltransduktion, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Georg W
authors.initials: GW
authors.lastname: Mayr
authors.affiliation: UKE Hamburg, Institut für Biochemie und Signaltransduktion, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: s.windhorst@uke.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Windhorst
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001549:Benzamides / Q000737:chemistry / Q000494:pharmacology; D001583:Benzoxazoles / Q000737:chemistry / Q000494:pharmacology; D020013:Calcium Signaling; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D057166:High-Throughput Screening Assays; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000473:pathology*; D062105:Molecular Docking Simulation; D053644:Naphthalimides / Q000737:chemistry / Q000494:pharmacology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors*; D011720:Pyrazoles / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C000600452:2-(3,5-dimethyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)-5,8-dinitro-1H-benzo(de)isoquinoline-1,3(2H)-dione; D000970:Antineoplastic Agents; D001549:Benzamides; D001583:Benzoxazoles; C000600453:N-(1,2-benzoaxol-3-yl)-4-methylbenzamide; D053644:Naphthalimides; D011720:Pyrazoles; D015544:Inositol 1,4,5-Trisphosphate; D017853:Phosphotransferases (Alcohol Group Acceptor); C051038:Inositol 1,4,5-trisphosphate 3-kinase
keywords: Cell proliferation; Cellular adhesion; Cellular uptake; InsP(3)Kinase; Migration; Small molecule inhibitors