The Protease Activated Receptor2 Promotes Rab5a Mediated Generation of Pro-metastatic Microvesicles

Sci Rep. 2018 May 9;8(1):7357. doi: 10.1038/s41598-018-25725-w.

Abstract

Metastasis, the hallmark of cancer propagation is attributed by the modification of phenotypic/functional behavior of cells to break attachment and migrate to distant body parts. Cancer cell-secreted microvesicles (MVs) contribute immensely in disease propagation. These nano-vesicles, generated from plasma membrane outward budding are taken up by nearby healthy cells thereby inducing phenotypic alterations in those recipient cells. Protease activated receptor 2 (PAR2), activated by trypsin, also contributes to cancer progression by increasing metastasis, angiogenesis etc. Here, we report that PAR2 activation promotes pro-metastatic MVs generation from human breast cancer cell line, MDA-MB-231. Rab5a, located at the plasma membrane plays vital roles in MVs biogenesis. We show that PAR2 stimulation promotes AKT phosphorylation which activates Rab5a by converting inactive Rab5a-GDP to active Rab5a-GTP. Active Rab5a polymerizes actin which critically regulates MVs shedding. Not only MVs generation, has this Rab5a activation also promoted cell migration and invasion. We reveal that Rab5a is over-expressed in human breast tumor specimen and contributes MVs generation in those patients. The involvement of p38 MAPK in MVs-induced cell metastasis has also been highlighted in the present study. Blockade of Rab5a activation can be a potential therapeutic approach to restrict MVs shedding and associated breast cancer metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / chemistry
  • Cell Movement
  • Cell-Derived Microparticles / pathology*
  • Enzyme Activation
  • Humans
  • Intracellular Space / metabolism
  • MCF-7 Cells
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptor, PAR-2 / metabolism*
  • Trypsin / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism
  • rab5 GTP-Binding Proteins / metabolism*

Substances

  • Actins
  • Receptor, PAR-2
  • Proto-Oncogene Proteins c-akt
  • p38 Mitogen-Activated Protein Kinases
  • Trypsin
  • rab5 GTP-Binding Proteins