title: Combretastatin (CA)-4 and its novel analogue CA-432 impair T-cell migration through the Rho/ROCK signalling pathway.
abstract: The capacity of T-lymphocytes to migrate and localise in tissues is important in their protective function against infectious agents, however, the ability of these cells to infiltrate the tumour microenvironment is a major contributing factor in the development of cancer. T-cell migration requires ligand (ICAM-1)/integrin (LFA-1) interaction, activating intracellular signalling pathways which result in a distinct polarised morphology, with an actin-rich lamellipodium and microtubule (MT)-rich uropod. Combretastatin (CA)-4 is a MT-destabilising agent that possesses potent anti-tumour properties. In this study, the effect of CA-4 and its novel analogue CA-432 on human T-cell migration was assessed. Cellular pretreatment with either of CA compounds inhibited the migration and chemotaxis of the T-cell line HuT-78 and primary peripheral blood lymphocyte (PBL) T-cells. This migration-inhibitory effect of CA compounds was due to the disruption of the MT network of T-cells through tubulin depolymerisation, reduced tubulin acetylation and decreased MT stability. In addition, both CA compounds induced the RhoA/RhoA associated kinase (ROCK) signalling pathway, leading to the phosphorylation of myosin light chain (MLC). Furthermore, the siRNA-mediated depletion of GEF-H1, a MT-associated nucleotide exchange factor that activates RhoA upon release from MTs, in T-cells prevented CA-induced phosphorylation of MLC and attenuated the formation of actin-rich membrane protrusions and cell contractility. These results suggest an important role for a GEF-H1/RhoA/ROCK/MLC signalling axis in mediating CA-induced contractility of T-cells. Therapeutic agents that target cytoskeletal proteins and are effective in inhibiting cell migration may open new avenues in the treatment of cancer and metastasis.
authors.affiliation: School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland. Electronic address: pollocjk@tcd.ie.
authors.forename: Jade K
authors.initials: JK
authors.lastname: Pollock
authors.affiliation: Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore. Electronic address: nkverma@ntu.edu.sg.
authors.forename: Navin K
authors.initials: NK
authors.lastname: Verma
authors.affiliation: School of Pharmacy, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland. Electronic address: oboyleni@tcd.ie.
authors.forename: Niamh M
authors.initials: NM
authors.lastname: O'Boyle
authors.affiliation: School of Pharmacy, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland. Electronic address: miriam.carr@approcess.com.
authors.forename: Miriam
authors.initials: M
authors.lastname: Carr
authors.affiliation: School of Pharmacy, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland. Electronic address: MMEEGAN@tcd.ie.
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Meegan
authors.affiliation: School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland. Electronic address: dzistrer@tcd.ie.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Zisterer
mesh_terms: D000107:Acetylation; D001632:Bibenzyls / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D058105:Polymerization; D015398:Signal Transduction / Q000187:drug effects*; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D001632:Bibenzyls; C040105:combretastatin; D054460:rho-Associated Kinases
keywords: CA-4; CA-432; Microtubules; Migration; T-cell