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March 17, 2012 ACS Pentasectional Meeting. Development and Screening of Transition Metal Complexes as CXCR4 Antagonists. Dr. Tim Hubin Department of Chemistry and Physics. Important role in embryonic development: Organogenesis (liver , heart) Stem cell movement
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March 17, 2012 ACS Pentasectional Meeting Development and Screening of Transition Metal Complexes as CXCR4 Antagonists Dr. Tim Hubin Department of Chemistry and Physics
Important role in embryonic development: Organogenesis (liver, heart) Stem cell movement Cerebellar neuron migration (formation of brain) Seven transmembrane G-protein-coupled receptor 27% of amino acids are Asp, His or Tyr. Expressed in : Leukocytes T-lymphocytes Endothelial cells Neuronal cells CXCR4 chemokine receptor Khan, A.; Greenman, J.; Archibald, S. J. Curr. Med. Chem. 2007, 14, 2257.
CXCL12 • 67 residue highly basic protein • Only known natural ligand (chemokine) for CXCR4 • Secreted by stromal, lung and liver cells, and lymph nodes • Attracts leukocytes to sites of inflammation and lymphoid organs
CXCR4-antagonists and HIV • Inhibitors against 5 steps of HIV replication cycle • Still need for new targets • Prototype bicyclams AMD3100
Blocking receptor functions CXCL12/HIV Drug Cell
Molecular shape Bosnich, B.; Poon, C. K.; Tobe, M. L. Inorg. Chem.,1965, 4,1102
Restrict to one configuration Onlytrans-II Onlycis V
AMD3100 Lewis, E. A.; Hubin, T. J.; Archibald, S. J. European Patent 1765826A2 .
Key Name Parameter - control.001 FL1-H + Control 717.019 FL1-H L2 717.010 FL1-H L1 717.009 FL1-H Binding to CXCR4 by flow cytometry Fluorescent antibody Receptor specific antibody Drug molecule CXCR4
Inhibition (of CXCL12) Assays Summary of mAb 12G5 binding to CXCR4 in the presence of bound antagonists.
Residence time, Cu-Cross Bridged G. McRobbie, A. Khan, G. Nicholson, L. Madden, J. Greenman C. Pannecouque, E. De Clercq, T. J. Hubin and S. J. Archibald, J. Am. Chem. Soc, 2009, 3416.
Antiviral Activity in MT-4 Cells L1 L2 L3
CXCR4 and Cancer Cell Metastasis • CXCL12 is normally responsible for trafficking of lymphocytes • CXCL12 is secreted by stromal, lung and liver cells, and lymph nodes • The interaction at the cell membrane is through CXCR4, which is over-expressed in some cancers • Potential mechanism of metastasis Normal cell Cancer cell
ANTI-CANCER ACTIVITY Invasion assays • Cell invasion assays in response to a chemokine gradient. • Initially used SJSA cells. • Experiments run in presence and absence of antagonist.
CXCL12 Control Drug/ no CXCL12 Drug + CXCL12
Cancer Cell Invasion Assay Invasion of SJSA cells in matrigel with CXCL12 (12.5 nM) and CXCR4 antagonists (20-200 nM). Cells were counted in five different fields (x40 obj) in duplicates. Mean of the values plotted. Asterisk represents significance (p < 0.01) from B. A = no CXCL12 and no antagonist; B = CXCL12 only; C = 20 nM Cu-Cross Bridged antagonist; D = 200 nM Cu-Cross Bridged antagonist; E = 20 nM AMD3100; F = 200 nM AMD3100.
Stem Cell Mobilization—OMRF (Barlic) • An acute administration of AMD3100 is known to rapidly mobilize bone marrow stem cells and progenitors. This mobilization is due to inactivation of the CXCR4-CXCL12 axis which holds progenitors in the bone marrow. • AMD3100 induces neutrophilia and leukocytosis, which reach their maximum 2 hours post-injection. • AMD3100 has not been noted to have an impact on monocytes. • C57BL/6 strain = a common strain of lab mouse, probably the most widely used "genetic background“ for use as models of human disease. They are the most widely used lab mouse strain, due to the availability of congenic strains, easy breeding, and robustness.
saline baseline AMD3100 SAJ5 Total neutrophil count (x103/ml) Total leukocyte count (x103/ml) Time (h): - 2 4 8 Time (h): - 2 4 8 Total monocyte count (x103/ml) Time (h): - 2 4 8
Current research group: Courtney Garcia (Chemistry/Medicine) Paul Won (Chemistry/Pharmacy) Justin Le (Chemistry/Pharmacy) Past members: Robert Ullom—University of Kansas (Medicine) Joe Blas—Creighton (Medicine) Danny Maples—OSU (Chemistry) Randall Maples—OSU (Chemistry) Dallas Matz—Arizona State University (Chemistry) Mike McClain—OU (Chemistry) Amy Cain—U. British Columbia (Chemistry) OrryBirdsong—UT Galveston (Medicine) Kimberly Roewe—OSU (Chemistry) KietNgyuen—SWOSU (Pharmacy) Josh Priddle—OSU (Medicine) Desiray Cannon (Chemistry) Katherine Coats (Chemistry) Natalie Simpson (Chemistry) Kevin Wilson (Chemistry) Acknowledgements Funding • OK-INBRE (NIH) • Research Corporation • SWOSU • Dr. Steve Archibald (Hull) • Dr. Abid Khan (Hull) • Prof. Erik De Clercq (Leuven) • Dr. Christophe Pannecouque(Leuven) • Dr. Dominique Schols (Leuven) • Prof. Tony Ng (KCL) • Dr. Jana Barlic (OMRF)
United States Weatherford—synthesis/characterization (Hubin) Oklahoma City—stem cell mobilization, atheroregression, obesity (Barlic) United Kingdom Hull—synthesis/characterization, CXCR4 binding, imaging, cancer metastases (Archibald) London—cancer cell imaging (Ng), PET Imaging, pharmacology (Blower) Belgium Leuven—anti-HIV properties (DeClercq, Pannecouque), Ca-Signaling (Schols)