A KSHV microRNA Directly Targets G Protein-Coupled Receptor Kinase 2 to Promote the Migration and Invasion of Endothelial Cells by Inducing CXCR2 and Activating AKT Signaling

PLoS Pathog. 2015 Sep 24;11(9):e1005171. doi: 10.1371/journal.ppat.1005171. eCollection 2015 Sep.

Abstract

Kaposi's sarcoma (KS) is a highly disseminated angiogenic tumor of endothelial cells linked to infection by Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV encodes more than two dozens of miRNAs but their roles in KSHV-induced tumor dissemination and metastasis remain unknown. Here, we found that ectopic expression of miR-K12-3 (miR-K3) promoted endothelial cell migration and invasion. Bioinformatics and luciferase reporter analyses showed that miR-K3 directly targeted G protein-coupled receptor (GPCR) kinase 2 (GRK2, official gene symbol ADRBK1). Importantly, overexpression of GRK2 reversed miR-K3 induction of cell migration and invasion. Furthermore, the chemokine receptor CXCR2, which was negatively regulated by GRK2, was upregulated in miR-K3-transduced endothelial cells. Knock down of CXCR2 abolished miR-K3-induced cell migration and invasion. Moreover, miR-K3 downregulation of GRK2 relieved its direct inhibitory effect on AKT. Both CXCR2 induction and the release of AKT from GRK2 were required for miR-K3 maximum activation of AKT and induction of cell migration and invasion. Finally, deletion of miR-K3 from the KSHV genome abrogated its effect on the GRK2/CXCR2/AKT pathway and KSHV-induced migration and invasion. Our data provide the first-line evidence that, by repressing GRK2, miR-K3 facilitates cell migration and invasion via activation of CXCR2/AKT signaling, which likely contribute to the dissemination of KSHV-induced tumors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Movement
  • Cells, Cultured
  • Endothelium, Vascular / immunology
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / pathology
  • Endothelium, Vascular / virology*
  • Enzyme Repression
  • G-Protein-Coupled Receptor Kinase 2 / antagonists & inhibitors*
  • G-Protein-Coupled Receptor Kinase 2 / genetics
  • G-Protein-Coupled Receptor Kinase 2 / metabolism
  • Gene Deletion
  • Herpesvirus 8, Human / immunology
  • Herpesvirus 8, Human / physiology*
  • Host-Pathogen Interactions*
  • Human Umbilical Vein Endothelial Cells / immunology
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Human Umbilical Vein Endothelial Cells / pathology
  • Human Umbilical Vein Endothelial Cells / virology
  • Humans
  • MicroRNAs / metabolism*
  • Mutation
  • Neoplasm Invasiveness
  • Proto-Oncogene Proteins c-akt / agonists
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA / metabolism
  • RNA Interference
  • RNA, Viral / metabolism*
  • Receptors, Interleukin-8B / agonists
  • Receptors, Interleukin-8B / genetics
  • Receptors, Interleukin-8B / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sarcoma, Kaposi / immunology
  • Sarcoma, Kaposi / metabolism
  • Sarcoma, Kaposi / pathology
  • Sarcoma, Kaposi / virology
  • Signal Transduction
  • Virus Internalization*

Substances

  • MicroRNAs
  • RNA, Viral
  • RNA, recombinant
  • Receptors, Interleukin-8B
  • Recombinant Proteins
  • RNA
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt
  • GRK2 protein, human
  • G-Protein-Coupled Receptor Kinase 2