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: Jade K Pollock, Navin K Verma, Niamh M O'Boyle, Miriam Carr, Mary J Meegan, Daniela M Zisterer
• Journal: Biochemical pharmacology (Biochem Pharmacol) Vol. 92 Issue 4 Pg. 544-57 (Dec 15 2014) ISSN: 1873-2968 [Electronic] England
• PMID: 25450669 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Bibenzyls
• combretastatin
• rho-Associated Kinases

Topics

• Acetylation
• Bibenzyls (chemistry, pharmacology)
• Cell Line
• Chemotaxis, Leukocyte (drug effects)
• Dose-Response Relationship, Drug
• Humans
• Microscopy, Fluorescence
• Microtubules (drug effects, metabolism)
• Phosphorylation
• Polymerization
• Signal Transduction (drug effects)
• T-Lymphocytes (cytology, drug effects)
• rho-Associated Kinases (metabolism)