Lysophosphatidic acid stimulates fas ligand microvesicle release from ovarian cancer cells

Cancer Immunol Immunother. 2005 Aug;54(8):807-14. doi: 10.1007/s00262-004-0642-5. Epub 2005 Jan 21.

Abstract

Previous reports support that lysophosphatidic acid (LPA) upregulates Fas ligand (FasL) cell surface presentation on the ovarian cancer cells. In this study, we aim to investigate soluble FasL (sFasL) secretion associated with the small membrane microvesicles upon LPA stimulation, and to analyze the roles of cytoskeletal reorganization in FasL transport induced by LPA. Ovarian cancer cells were stimulated with LPA and spent media were harvested, concentrated, and ultracentrifugated to collect the supernatant and pellet. Western blot suggested that sFasL released from ovarian cancer cells were the mature form, and these sFasL are released with the small membrane microvesicles. Flow cytometry showed that the majority of microvesicles secreted contained FasL on their membrane, and these small membrane microvesicles are bioactive against activated human T lymphocytes. The microtubule-disrupting reagent nocodazole, not the actin-filament-disrupting reagent cytochalasin D pretreatment blocked FasL-expressing small membrane microvesicle release stimulated by LPA, suggesting that microtubules play an essential role in FasL microvesicle transport and exocytosis. LPA may promote ovarian cancer metastasis by counterattacking peritoneal cavity anti-tumor immunity.

Publication types

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

MeSH terms

  • Blotting, Western
  • Cytoskeleton / physiology
  • Enzyme-Linked Immunosorbent Assay
  • Fas Ligand Protein
  • Female
  • Flow Cytometry
  • Humans
  • Lysophospholipids / pharmacology*
  • Membrane Glycoproteins / biosynthesis*
  • Microtubules / physiology
  • Neoplasm Metastasis / physiopathology*
  • Ovarian Neoplasms / pathology*
  • Tumor Cells, Cultured
  • Up-Regulation

Substances

  • FASLG protein, human
  • Fas Ligand Protein
  • Lysophospholipids
  • Membrane Glycoproteins
  • lysophosphatidic acid