Generic placeholder image

Current Molecular Pharmacology


ISSN (Print): 1874-4672
ISSN (Online): 1874-4702


Convergence of Canonical and Non-Canonical Wnt Signal: Differential Kat3 Coactivator Usage

Author(s): Keane K.Y. Lai*, Cu Nguyen, Kyung-Soon Lee, Albert Lee, David P. Lin, Jia-Ling Teo and Michael Kahn*

Volume 12 , Issue 3 , 2019

Page: [167 - 183] Pages: 17

DOI: 10.2174/1874467212666190304121131


Background: The ancient and highly evolutionarily conserved Wnt signaling pathway is critical in nearly all tissues and organs for an organism to develop normally from embryo through adult. Wnt signaling is generally parsed into “canonical” or Wnt-β-catenin-dependent or “non-canonical” β-catenin-independent signaling. Even though designating Wnt signaling as either canonical or noncanonical allows for easier conceptual discourse about this signaling pathway, in fact canonical and non-canonical Wnt crosstalk regulates complex nonlinear networks.

Objective: In this perspective, we discuss the integration of canonical and non-canonical Wnt signaling via differential Kat3 (CBP and p300) coactivator usage, thereby regulating and coordinating gene expression programs associated with both proliferation and cellular differentiation and morphogenesis.

Methods: Pharmacologic inhibitors, cell culture, real-time PCR, chromatin immunoprecipitation, protein immunoprecipitation, Western blotting, reporter-luciferase, protein purification, site-directed mutagenesis, in vitro phosphorylation and binding assays, and immunofluorescence were utilized.

Conclusion: Coordinated integration between both canonical and non-canonical Wnt pathways appears to be crucial not only in the control of fundamental morphologic processes but also in the regulation of normal as well as pathologic events. Such integration between both canonical and non-canonical Wnt signaling is presumably effected via reversible phosphorylation mechanism (e.g., protein kinase C) to regulate differential β -catenin/Kat3 coactivator usage in order to coordinate proliferation with differentiation and adhesion.

Keywords: Wnt, canonical, non-canonical, CBP, p300, Kat3 coactivator.

Graphical Abstract
Nelson, W.J.; Nusse, R. Convergence of Wnt, beta-catenin, and cadherin pathways. Science, 2004, 303, 1483-1487.
de Lau, W.; Peng, W.C.; Gros, P.; Clevers, H. The R-spondin/Lgr5/Rnf43 module: Regulator of Wnt signal strength. Genes Dev., 2014, 28, 305-316.
Reya, T.; Duncan, A.W.; Ailles, L.; Domen, J.; Scherer, D.C.; Willert, K.; Hintz, L.; Nusse, R.; Weissman, I.L. A role for Wnt signalling in self-renewal of haematopoietic stem cells. Nature, 2003, 423, 409-414.
Chenn, A.; Walsh, C.A. Regulation of cerebral cortical size by control of cell cycle exit in neural precursors. Science, 2002, 297, 365-369.
Hirabayashi, Y.; Itoh, Y.; Tabata, H.; Nakajima, K.; Akiyama, T.; Masuyama, N.; Gotoh, Y. The Wnt/beta-catenin pathway directs neuronal differentiation of cortical neural precursor cells. Development, 2004, 131, 2791-2801.
Veeman, M.T.; Axelrod, J.D.; Moon, R.T. A second canon. Functions and mechanisms of beta-catenin-independent Wnt signaling. Dev. Cell, 2003, 5, 367-377.
Keller, R. Shaping the vertebrate body plan by polarized embryonic cell movements. Science, 2002, 298, 1950-1954.
Mlodzik, M. Planar cell polarization: do the same mechanisms regulate Drosophila tissue polarity and vertebrate gastrulation? Trends Genet., 2002, 18, 564-571.
Torres, M.A.; Yang-Snyder, J.A.; Purcell, S.M.; DeMarais, A.A.; McGrew, L.L.; Moon, R.T. Activities of the Wnt-1 class of secreted signaling factors are antagonized by the Wnt-5A class and by a dominant negative cadherin in early Xenopus development. J. Cell Biol., 1996, 133, 1123-1137.
Ishitani, T.; Ninomiya-Tsuji, J.; Nagai, S.; Nishita, M.; Meneghini, M.; Barker, N.; Waterman, M.; Bowerman, B.; Clevers, H.; Shibuya, H.; Matsumoto, K. The TAK1-NLK-MAPK-related pathway antagonizes signalling between beta-catenin and transcription factor TCF. Nature, 1999, 399, 798-802.
Ishitani, T.; Kishida, S.; Hyodo-Miura, J.; Ueno, N.; Yasuda, J.; Waterman, M.; Shibuya, H.; Moon, R.T.; Ninomiya-Tsuji, J.; Matsumoto, K. The TAK1-NLK mitogen-activated protein kinase cascade functions in the Wnt-5a/Ca(2+) pathway to antagonize Wnt/beta-catenin signaling. Mol. Cell. Biol., 2003, 23, 131-139.
Park, M.; Moon, R.T. The planar cell-polarity gene stbm regulates cell behaviour and cell fate in vertebrate embryos. Nat. Cell Biol., 2002, 4, 20-25.
Topol, L.; Jiang, X.; Choi, H.; Garrett-Beal, L.; Carolan, P.J.; Yang, Y. Wnt-5a inhibits the canonical Wnt pathway by promoting GSK-3-independent beta-catenin degradation. J. Cell Biol., 2003, 162, 899-908.
Westfall, T.A.; Brimeyer, R.; Twedt, J.; Gladon, J.; Olberding, A.; Furutani-Seiki, M.; Slusarski, D.C. Wnt-5/pipetail functions in vertebrate axis formation as a negative regulator of Wnt/beta-catenin activity. J. Cell Biol., 2003, 162, 889-898.
Emami, K.H.; Nguyen, C.; Ma, H.; Kim, D.H.; Jeong, K.W.; Eguchi, M.; Moon, R.T.; Teo, J.L.; Oh, S.W.; Kim, H.Y.; Moon, S.H.; Ha, J.R.; Kahn, M. A small molecule inhibitor of beta-catenin/CREB-binding protein transcription [corrected] Proc. Natl. Acad. Sci. USA, 2004, 101, 12682-12687.
Ma, H.; Nguyen, C.; Lee, K.S.; Kahn, M. Differential roles for the coactivators CBP and p300 on TCF/beta-catenin-mediated survivin gene expression. Oncogene, 2005, 24, 3619-3631.
Teo, J.L.; Ma, H.; Nguyen, C.; Lam, C.; Kahn, M. Specific inhibition of CBP/beta-catenin interaction rescues defects in neuronal differentiation caused by a presenilin-1 mutation. Proc. Natl. Acad. Sci. USA, 2005, 102, 12171-12176.
McMillan, M.; Kahn, M. Investigating Wnt signaling: a chemogenomic safari. Drug Discov. Today, 2005, 10, 1467-1474.
Miyabayashi, T.; Teo, J.L.; Yamamoto, M.; McMillan, M.; Nguyen, C.; Kahn, M. Wnt/beta-catenin/CBP signaling maintains long-term murine embryonic stem cell pluripotency. Proc. Natl. Acad. Sci. USA, 2007, 104, 5668-5673.
Higuchi, Y.; Nguyen, C.; Yasuda, S.Y.; McMillan, M.; Hasegawa, K.; Kahn, M. Specific Direct Small Molecule p300/β-Catenin Antagonists Maintain Stem Cell Potency. Curr. Mol. Pharmacol., 2016, 9, 272-279.
Thomas, P.D.; Kahn, M. Kat3 coactivators in somatic stem cells and cancer stem cells: biological roles, evolution, and pharmacologic manipulation. Cell Biol. Toxicol., 2016, 32, 61-81.
Rieger, M.E.; Zhou, B.; Solomon, N.; Sunohara, M.; Li, C.; Nguyen, C.; Liu, Y.; Pan, J.H.; Minoo, P.; Crandall, E.D.; Brody, S.L.; Kahn, M.; Borok, Z. p300/β-Catenin Interactions Regulate Adult Progenitor Cell Differentiation Downstream of WNT5a/Protein Kinase C (PKC). J. Biol. Chem., 2016, 291, 6569-6582.
Eguchi, M.; Nguyen, C.; Lee, S.C.; Kahn, M. ICG-001, a novel small molecule regulator of TCF/beta-catenin transcription. Med. Chem., 2005, 1, 467-472.
Miyabayashi, T.; Yamamoto, M. Cell differentiation inhibiting agent, cell culture method using the same, culture medium, and cultured cell line. U.S. Patent 10, 875, 194, July 25, 2005.
Spencer, V.A.; Sun, J.M.; Li, L.; Davie, J.R. Chromatin immunoprecipitation: a tool for studying histone acetylation and transcription factor binding. Methods, 2003, 31, 67-75.
Eckner, R.; Ludlow, J.W.; Lill, N.L.; Oldread, E.; Arany, Z.; Modjtahedi, N.; DeCaprio, J.A.; Livingston, D.M.; Morgan, J.A. Association of p300 and CBP with simian virus 40 large T antigen. Mol. Cell. Biol., 1996, 16, 3454-3464.
Weiner, M.P.; Costa, G.L.; Schoettlin, W.; Cline, J.; Mathur, E.; Bauer, J.C. Site-directed mutagenesis of double-stranded DNA by the polymerase chain reaction. Gene, 1994, 151, 119-123.
Johnson, J.E.; Edwards, A.S.; Newton, A.C. A putative phosphatidylserine binding motif is not involved in the lipid regulation of protein kinase C. J. Biol. Chem., 1997, 272, 30787-30792.
Basch, M.L.; Ohyama, T.; Segil, N.; Groves, A.K. Canonical Notch signaling is not necessary for prosensory induction in the mouse cochlea: insights from a conditional mutant of RBPjkappa. J. Neurosci., 2011, 31, 8046-8058.
Shtutman, M.; Zhurinsky, J.; Simcha, I.; Albanese, C.; D’Amico, M.; Pestell, R.; Ben-Ze’ev, A. The cyclin D1 gene is a target of the beta-catenin/LEF-1 pathway. Proc. Natl. Acad. Sci. USA, 1999, 96, 5522-5527.
Tetsu, O.; McCormick, F. Beta-catenin regulates expression of cyclin D1 in colon carcinoma cells. Nature, 1999, 398, 422-426.
Yan, D.; Wiesmann, M.; Rohan, M.; Chan, V.; Jefferson, A.B.; Guo, L.; Sakamoto, D.; Caothien, R.H.; Fuller, J.H.; Reinhard, C.; Garcia, P.D.; Randazzo, F.M.; Escobedo, J.; Fantl, W.J.; Williams, L.T. Elevated expression of axin2 and hnkd mRNA provides evidence that Wnt/beta -catenin signaling is activated in human colon tumors. Proc. Natl. Acad. Sci. USA, 2001, 98, 14973-14978.
He, T.C.; Sparks, A.B.; Rago, C.; Hermeking, H.; Zawel, L.; da Costa, L.T.; Morin, P.J.; Vogelstein, B.; Kinzler, K.W. Identification of c-MYC as a target of the APC pathway. Science, 1998, 281, 1509-1512.
Mann, B.; Gelos, M.; Siedow, A.; Hanski, M.L.; Gratchev, A.; Ilyas, M.; Bodmer, W.F.; Moyer, M.P.; Riecken, E.O.; Buhr, H.J.; Hanski, C. Target genes of beta-catenin-T cell-factor/lymphoid-enhancer-factor signaling in human colorectal carcinomas. Proc. Natl. Acad. Sci. USA, 1999, 96, 1603-1608.
Kumar, S.R.; Scehnet, J.S.; Ley, E.J.; Singh, J.; Krasnoperov, V.; Liu, R.; Manchanda, P.K.; Ladner, R.D.; Hawes, D.; Weaver, F.A.; Beart, R.W.; Singh, G.; Nguyen, C.; Kahn, M.; Gill, P.S. Preferential induction of EphB4 over EphB2 and its implication in colorectal cancer progression. Cancer Res., 2009, 69, 3736-3745.
Wilson, A.; Murphy, M.J.; Oskarsson, T.; Kaloulis, K.; Bettess, M.D.; Oser, G.M.; Pasche, A.C.; Knabenhans, C.; Macdonald, H.R.; Trumpp, A. c-Myc controls the balance between hematopoietic stem cell self-renewal and differentiation. Genes Dev., 2004, 18, 2747-2763.
Quinn, L.M.; Secombe, J.; Hime, G.R. Myc in stem cell behaviour: Insights from Drosophila. Adv. Exp. Med. Biol., 2013, 786, 269-285.
Rebel, V.I.; Kung, A.L.; Tanner, E.A.; Yang, H.; Bronson, R.T.; Livingston, D.M. Distinct roles for CREB-binding protein and p300 in hematopoietic stem cell self-renewal. Proc. Natl. Acad. Sci. USA, 2002, 99, 14789-14794.
Holmen, S.L.; Salic, A.; Zylstra, C.R.; Kirschner, M.W.; Williams, B.O. A novel set of Wnt-Frizzled fusion proteins identifies receptor components that activate beta -catenin-dependent signaling. J. Biol. Chem., 2002, 277, 34727-34735.
Kühl, M.; Sheldahl, L.C.; Malbon, C.C.; Moon, R.T. Ca(2+)/calmodulin-dependent protein kinase II is stimulated by Wnt and Frizzled homologs and promotes ventral cell fates in Xenopus. J. Biol. Chem., 2000, 275, 12701-12711.
Sheldahl, L.C.; Park, M.; Malbon, C.C.; Moon, R.T. Protein kinase C is differentially stimulated by Wnt and Frizzled homologs in a G-protein-dependent manner. Curr. Biol., 1999, 9, 695-698.
Weeraratna, A.T.; Jiang, Y.; Hostetter, G.; Rosenblatt, K.; Duray, P.; Bittner, M.; Trent, J.M. Wnt5a signaling directly affects cell motility and invasion of metastatic melanoma. Cancer Cell, 2002, 1, 279-288.
Yuan, L.W.; Gambee, J.E. Phosphorylation of p300 at serine 89 by protein kinase C. J. Biol. Chem., 2000, 275, 40946-40951.
Szallasi, Z.; Smith, C.B.; Pettit, G.R.; Blumberg, P.M. Differential regulation of protein kinase C isozymes by bryostatin 1 and phorbol 12-myristate 13-acetate in NIH 3T3 fibroblasts. J. Biol. Chem., 1994, 269, 2118-2124.
Davies, S.P.; Reddy, H.; Caivano, M.; Cohen, P. Specificity and mechanism of action of some commonly used protein kinase inhibitors. Biochem. J., 2000, 351, 95-105.
Gupta, K.P.; Ward, N.E.; Gravitt, K.R.; Bergman, P.J.; O’Brian, C.A. Partial reversal of multidrug resistance in human breast cancer cells by an N-myristoylated protein kinase C-alpha pseudosubstrate peptide. J. Biol. Chem., 1996, 271, 2102-2111.
Corcoran, E.E.; Joseph, J.D.; MacDonald, J.A.; Kane, C.D.; Haystead, T.A.; Means, A.R. Proteomic analysis of calcium/calmodulin-dependent protein kinase I and IV in vitro substrates reveals distinct catalytic preferences. J. Biol. Chem., 2003, 278, 10516-10522.
Yang, W.; Hong, Y.H.; Shen, X.Q.; Frankowski, C.; Camp, H.S.; Leff, T. Regulation of transcription by AMP-activated protein kinase: phosphorylation of p300 blocks its interaction with nuclear receptors. J. Biol. Chem., 2001, 276, 38341-38344.
Liu, Y.; Dentin, R.; Chen, D.; Hedrick, S.; Ravnskjaer, K.; Schenk, S.; Milne, J.; Meyers, D.J.; Cole, P.; Yates, J.; Olefsky, J.; Guarente, L.; Montminy, M. A fasting inducible switch modulates gluconeogenesis via activator/coactivator exchange. Nature, 2008, 456, 269-273.
Gusterson, R.J.; Yuan, L.W.; Latchman, D.S. Distinct serine residues in CBP and p300 are necessary for their activation by phenylephrine. Int. J. Biochem. Cell Biol., 2004, 36, 893-899.
Yuan, L.W.; Soh, J.W.; Weinstein, I.B. Inhibition of histone acetyltransferase function of p300 by PKCdelta. Biochim. Biophys. Acta, 2002, 1592, 205-211.
Bittner, M.; Meltzer, P.; Chen, Y.; Jiang, Y.; Seftor, E.; Hendrix, M.; Radmacher, M.; Simon, R.; Yakhini, Z.; Ben-Dor, A.; Sampas, N.; Dougherty, E.; Wang, E.; Marincola, F.; Gooden, C.; Lueders, J.; Glatfelter, A.; Pollock, P.; Carpten, J.; Gillanders, E.; Leja, D.; Dietrich, K.; Beaudry, C.; Berens, M.; Alberts, D.; Sondak, V. Molecular classification of cutaneous malignant melanoma by gene expression profiling. Nature, 2000, 406, 536-540.
Yan, D.; Wallingford, J.B.; Sun, T.Q.; Nelson, A.M.; Sakanaka, C.; Reinhard, C.; Harland, R.M.; Fantl, W.J.; Williams, L.T. Cell autonomous regulation of multiple Dishevelled-dependent pathways by mammalian Nkd. Proc. Natl. Acad. Sci. USA, 2001, 98, 3802-3807.
Dabdoub, A.; Kelley, M.W. Planar cell polarity and a potential role for a Wnt morphogen gradient in stereociliary bundle orientation in the mammalian inner ear. J. Neurobiol., 2005, 64, 446-457.
Fujita, H.; Orita, Y. An inner ear anomaly in golden hamsters. Am. J. Otolaryngol., 1988, 9, 224-231.
Comis, S.D.; Pickles, J.O.; Osborne, M.P.; Pepper, C.B. Tip-link organization in anomalously-oriented hair cells of the guinea pig cochlea. Hear. Res., 1989, 40, 205-211.
Fujita, H. Mutant golden hamsters with an abnormal outer hair cell stereociliary arrangement. Hear. Res., 1990, 44, 63-69.
Furness, D.N.; Hackney, C.M.; Hynd, A.N. Rotated stereociliary bundles and their relationship with the tectorial membrane in the guinea pig cochlea. Acta Otolaryngol., 1990, 109, 66-75.
Yoshida, N.; Liberman, M.C. Stereociliary anomaly in the guinea pig: effects of hair bundle rotation on cochlear sensitivity. Hear. Res., 1999, 131, 29-38.
Qian, D.; Jones, C.; Rzadzinska, A.; Mark, S.; Zhang, X.; Steel, K.P.; Dai, X.; Chen, P. Wnt5a functions in planar cell polarity regulation in mice. Dev. Biol., 2007, 306, 121-133.
Sasaki, T.; Hwang, H.; Nguyen, C.; Kloner, R.A.; Kahn, M. The small molecule Wnt signaling modulator ICG-001 improves contractile function in chronically infarcted rat myocardium. PLoS One, 2013, 8 e75010
Sasaki, T.; Kahn, M. Inhibition of β-catenin/p300 interaction proximalizes mouse embryonic lung epithelium. Transl. Respir. Med., 2014, 2, 8.
Huelsken, J.; Behrens, J. The Wnt signalling pathway. J. Cell Sci., 2002, 115, 3977-3978.
Steinhart, Z.; Angers, S. Wnt signaling in development and tissue homeostasis. Development, 2018, 145(11) pii: dev146589.
May-Simera, H.L.; Kelley, M.W. Cilia, Wnt signaling, and the cytoskeleton. Cilia, 2012, 1, 7.
Teo, J.L.; Kahn, M. The Wnt signaling pathway in cellular proliferation and differentiation: A tale of two coactivators. Adv. Drug Deliv. Rev., 2010, 62, 1149-1155.
Cavodeassi, F.; Carreira-Barbosa, F.; Young, R.M.; Concha, M.L.; Allende, M.L.; Houart, C.; Tada, M.; Wilson, S.W. Early stages of zebrafish eye formation require the coordinated activity of Wnt11, Fz5, and the Wnt/beta-catenin pathway. Neuron, 2005, 47, 43-56.
Winter, C.G.; Wang, B.; Ballew, A.; Royou, A.; Karess, R.; Axelrod, J.D.; Luo, L. Drosophila Rho-associated kinase (Drok) links Frizzled-mediated planar cell polarity signaling to the actin cytoskeleton. Cell, 2001, 105, 81-91.
Habas, R.; Kato, Y.; He, X. Wnt/Frizzled activation of Rho regulates vertebrate gastrulation and requires a novel Formin homology protein Daam1. Cell, 2001, 107, 843-854.
Habas, R.; Dawid, I.B.; He, X. Coactivation of Rac and Rho by Wnt/Frizzled signaling is required for vertebrate gastrulation. Genes Dev., 2003, 17, 295-309.
Penzo-Mendèz, A.; Umbhauer, M.; Djiane, A.; Boucaut, J.C.; Riou, J.F. Activation of Gbetagamma signaling downstream of Wnt-11/Xfz7 regulates Cdc42 activity during Xenopus gastrulation. Dev. Biol., 2003, 257, 302-314.
Manegold, P.; Lai, K.K.Y.; Wu, Y.; Teo, J.L.; Lenz, H.J.; Genyk, Y.S.; Pandol, S.J.; Wu, K.; Lin, D.P.; Chen, Y.; Nguyen, C.; Zhao, Y.; Kahn, M. Differentiation Therapy Targeting the β-Catenin/CBP Interaction in Pancreatic Cancer. Cancers (Basel), 2018, 10(4), pii. E95.
Yamanaka, H.; Moriguchi, T.; Masuyama, N.; Kusakabe, M.; Hanafusa, H.; Takada, R.; Takada, S.; Nishida, E. JNK functions in the non-canonical Wnt pathway to regulate convergent extension movements in vertebrates. EMBO Rep., 2002, 3, 69-75.
Kühl, M.; Sheldahl, L.C.; Park, M.; Miller, J.R.; Moon, R.T. The Wnt/Ca2+ pathway: a new vertebrate Wnt signaling pathway takes shape. Trends Genet., 2000, 16, 279-283.
Sato, N.; Meijer, L.; Skaltsounis, L.; Greengard, P.; Brivanlou, A.H. Maintenance of pluripotency in human and mouse embryonic stem cells through activation of Wnt signaling by a pharmacological GSK-3-specific inhibitor. Nat. Med., 2004, 10, 55-63.
Boland, G.M.; Perkins, G.; Hall, D.J.; Tuan, R.S. Wnt 3a promotes proliferation and suppresses osteogenic differentiation of adult human mesenchymal stem cells. J. Cell. Biochem., 2004, 93, 1210-1230.
Mohammed, M.K.; Shao, C.; Wang, J.; Wei, Q.; Wang, X.; Collier, Z.; Tang, S.; Liu, H.; Zhang, F.; Huang, J.; Guo, D.; Lu, M.; Liu, F.; Liu, J.; Ma, C.; Shi, L.L.; Athiviraham, A.; He, T.C.; Lee, M.J. Wnt/β-catenin signaling plays an ever-expanding role in stem cell self-renewal, tumorigenesis and cancer chemoresistance. Genes Dis., 2016, 3, 11-40.
Koyanagi, M.; Haendeler, J.; Badorff, C.; Brandes, R.P.; Hoffmann, J.; Pandur, P.; Zeiher, A.M.; Kühl, M.; Dimmeler, S. Non-canonical Wnt signaling enhances differentiation of human circulating progenitor cells to cardiomyogenic cells. J. Biol. Chem., 2005, 280, 16838-16842.
Schulte, G.; Bryja, V.; Rawal, N.; Castelo-Branco, G.; Sousa, K.M.; Arenas, E. Purified Wnt-5a increases differentiation of midbrain dopaminergic cells and dishevelled phosphorylation. J. Neurochem., 2005, 92, 1550-1553.
Xiao, Q.; Chen, Z.; Jin, X.; Mao, R. The many postures of noncanonical Wnt signaling in development and diseases. Biomed. Pharmacother., 2017, 93, 359-369.
Wallingford, J.B.; Fraser, S.E.; Harland, R.M. Convergent extension: the molecular control of polarized cell movement during embryonic development. Dev. Cell, 2002, 2, 695-706.
Zhao, Y.; Masiello, D.; McMillian, M.; Nguyen, C.; Wu, Y.; Melendez, E.; Smbatyan, G.; Kida, A.; He, Y.; Teo, J.L.; Kahn, M. CBP/catenin antagonist safely eliminates drug-resistant leukemia-initiating cells. Oncogene, 2016, 35, 3705-3717.
Kim, Y.M.; Gang, E.J.; Kahn, M. CBP/Catenin antagonists: Targeting LSCs’ Achilles heel. Exp. Hematol., 2017, 52, 1-11.
Graves, J.D. Krebs, E.G. Protein phosphorylation and signal transduction. Pharmacol. Ther., 1999, 82, 111-121.

© 2022 Bentham Science Publishers | Privacy Policy